Author Topic: Challenger STS-6 – A Walk into History  (Read 248785 times)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #640 on: 11/10/2013 01:33 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #641 on: 11/10/2013 01:37 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #642 on: 11/10/2013 01:43 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #643 on: 11/10/2013 01:51 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #644 on: 11/10/2013 01:59 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #645 on: 11/10/2013 02:08 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #646 on: 11/10/2013 02:10 am »
David Dick (CBS/Edwards): The astronauts have left their spacecraft now; they appeared to be in fine shape as they walked around the airship (Huh?) that had served them so well for the past five days. Next stop for the crew will be the medical debriefing, and after that the astronauts will make their first public appearance. The landing here at Edwards Air Force Base was smooth despite a 17-knot headwind. Huge crowds turned out to welcome home the Challenger following its successful maiden voyage. As many as 100,000 spectators were on hand. David Dick, CBS News, Edwards Air Force Base, California.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #647 on: 11/10/2013 02:12 am »
SEA LEGS

“You seemed a little unsteady on your feet on the runway out there coming down the ramp,” Mission Specialist Story Musgrave was asked by a reporter during the pots-flight crew conference. “Did this relate to the experiments you were doing that were trying to gain some insight into Space Adaptation Syndrome? And as MD, can you offer any insights now that you’ve been through a mission?”

“You have a little sea legs when you get back home,” answered Musgrave. “P.J. warned us coming down the chute there that you’re going to feel heavier and as he alluded to when you start pulling the g’s there you do feel heavier. You feel like maybe you weigh 180 pounds instead of 150 or something like that. The g’s, if you’re reading g’s on the meter and they’re .8, maybe they feel like 1.2 or 1.3. But, you know, in terms of my sea legs, and all of our sea legs getting back home, that probably relates to adaptation back to one g from the five days of zero g, and whatever aerobatics and things I did in the zero-g environment. But I had sea legs coming back for about a day or so. The day after, I played some racquetball and went running and played about as good a game as I did the night before I left. So, that’s maybe about a 24-hour phenomenon.”

“Frankly,” interjected Commander Weitz, “I was surprised by that, of the subjective sense of how great an acceleration field you’re in after only five days. It wasn’t as marked as it was on Skylab after 28 days, but I expected that. I just frankly didn’t expect it here and mentioned what it felt like during the entry. But when it came time to bail out, and Bo had a couple of tasks to do and, I think, he looked around for some help once as he was all alone on the flight deck. The rest of us, we were ready to get out. But as I stood up out of the seat to step over the center console, it just absolutely flabbergasted me as to what my sensation was as I raised up out of the seat. I was immediately subjectively in a two-g field. And I think that was the sea legs, as Story put it, which is a very good way to put it.”

“You know, you don’t have that sensation if you just stand,” Weitz explained. “But it’s as soon as you move your head, or actually it’s not only your head, it’s your limbs. But I really think it’s your brain. Your total system got used to working for several days, in this case five, without any sensible acceleration environment. And now we put one g on top of that. And I frankly think that you get cross coupling; it’s just like precession of a gyro. Your internal gyro, if you stand still, doesn’t bother you. As soon as you move your head this way, and as a matter of fact I did it in the post-flight physical, you could see, if you close your eyes and move your head rapidly, your gyro precesses a little bit and you tend to wobble, because you’re getting a false impression. But, as Story said, I think it was still noticeable the morning of the next day; but by the end of the day after landing that it wasn’t there.”


(STS-6 PAO/Air-to-ground and press briefing transcripts; CBS News radio coverage and ABC News TV Special Report, Apr. 4, 1983; JSC Space News Roundup, Apr. 13, 1983; STS-7 Rockwell International Press Kit; Melvyn Smith, “An Illustrated History of Space Shuttle,” Haynes Publishing Group, 1985; David Shayler, “Shuttle Challenger,” Prentice Hall Press, 1987; Paul Weitz, NASA JSC Oral History Project interview, Mar. 26, 2000; Karol Bobko, NASA JSC Oral History Project, Feb. 12, 2002; Ben Evans, “Space Shuttle Challenger,” Springer/Praxis 2007 – edited and supplemented)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #648 on: 11/10/2013 02:14 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #649 on: 11/10/2013 02:17 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #650 on: 11/10/2013 02:20 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #651 on: 11/10/2013 02:23 am »
How was that for a mission?

“I think the mission, first of all, has accomplished the proof of the pudding, so to speak, in the second vehicle that was built. I think that is one of the most important things, to us anyway, that this machine that we built, acts like it was supposed to act. And we’re, of course, continually learning how 099 is acting. I might say that I, from an engineering standpoint, am amazed that we could, on a first flight like this, have only the few problems we had. But I think to us, to me anyway, that it’s kind of a proof flight and we’re finding out and providing that it works the way it was built to work. Now, the other thing, of course, that it is a really good capability is the demonstration that we can, although it almost didn’t happen, that we can put TDRS and those type vehicles up toward synchronous orbit. And I think that’s a milestone. I understand that the TDRS is one of the largest satellites ever put that high into synchronous orbit, and I think that is a great capability.”

- Gary Coen, STS-6 Flight Director


THANKS FOR A GOOD RIDE

PAO: Good afternoon, ladies and gentlemen. This is the STS-6 post landing press conference from NASA Dryden Flight Research Facility. Before we begin I have a few announcements. First, the STS-6 orbiter status press conference is scheduled for 11:00 a.m. Pacific Standard Time tomorrow, Sunday, April 10. Another, an estimated 100,000 visitors have gathered here today to view the landing of the Challenger and our STS-6 crew.

Following today’s press conference, the flight crew will be welcomed in a ceremony at the Dryden Flight Research Facility. Attending the ceremony will be the STS-6 crew, who will make a few remarks, as will NASA Administrator James M. Beggs, California Governor George Dukemagien, and the Air Force Flight Test Center’s Major General Peter W. Augers.

With us today for the STS-6 post landing press conference is Lt. General James A. Abrahamson, NASA Associate Administrator for Spaceflight, and Mr. Ed Smylie, Associate Administrator for Space Tracking and Data Systems…

Abrahamson: Well, how was that for a mission? Well, let’s see… The crew was out at 11:24 (a.m. PST). They’re in great shape; they’ve been in great shape for months actually, and really did a superb job on the mission. The mission clearly was, with one exception – and the drama we’ll leave to Mr. Smylie to talk about, the drama department here – with the exception of the problem areas that we had during the deployment of the IUS and the separation of the TDRS satellite, the mission was just incredibly routine. And it really meant that the Challenger is just a superb spacecraft.

Let me give you a feel for what this is like. First of all, we keep track of anomalies; it’s just like a maintenance record that some of you keep on your automobiles. Some maybe, like me, don’t do it too well. But, these anomalies we pile up during the missions and, of course, go to work on them well before the mission is complete.

On STS-1, remember this is a long time ago now, but this was the first flight of the Columbia and it was only a two-day flight, and there were 82 anomalies of the system. Now, that’s not just the Columbia itself, but the whole system itself. Each flight got better; down to the last flight of the Columbia it was all the way down to 27.

And I think I’ve said in the past that we really like used spacecraft. Well, of course, you know we had a rather long delayed period on our new spacecraft, and we didn’t really like the new engines, or the fact that we had to have a period in which we had… we shook this one out. But we ended up the flight as of just prior to reentry with only 22 anomalies, which meant that we’re just continuing down this learning curve in just really great shape. So I’m delighted.

Now, you all know that, and you probably see on TV, that we have some areas where we have lost some blankets on the OMS pods. Those are advanced thermal protection system blankets. Actually we have three: One that was kind of ripped off in the front part of the pod and then two on each side that are kind of bent and damaged and flap just a little bit.

We don’t think that there was any thermal problem at all. Underneath that we have our RTV, and if you could see on the RTV it looked good and red, so there was nothing really burnt at all associated with that. On the starboard side we had an equivalent sort of problem, and there are three small pieces that are missing. We are getting rather, I won’t say blasé, but we are… we know that that sort of thing happens and we’ll resolve that very easily. So, I guess that’s the key point.

There’s one other indicator of how routine the mission was, and this is a good strong indicator. It’s one that is of great interest to all of the crews that work around the clock at Johnson. That is that we did not have to do any significant replanning of the mission itself. On all of our past missions we have had some adjustment that we would make here and there in the timeline, and change some of the things. And that meant that a ground crew was working overnight to change the sequence or to send up new checklists for the flight crew, and it meant changes.

This time it was flown exactly as planned, including a marvelous EVA. So we’re just delighted with the entire mission. And of course we’re also very pleased that we’re at a situation now where it clearly looks like we can recover the TDRS spacecraft. And that really was a drama period, and it was people that allowed us to recover from some bad things that happened to us… also, some good things happened to us. And notice, I don’t say luck here. As to the bad things that happened, we have an investigation team – that’s already met – that is going after those things and will resolve those… the things on the IUS. The good things that happened are a result of the teams being ready, having been well trained and able to work together. And this a far-flung team that worked across the country. And Ed is going to talk to you about just what that was like. Ed, maybe you’d like to summarize that a little bit.

Smylie: Okay. If only my part of this could be as routine as your part, Abe. I’d like to say a few things before I get to that. In particular, as a customer to the STS system for this mission, I’d like to express my admiration and appreciation to Abe and the crew and all of the people in the manned spaceflight organization that took us to the point of deployment so flawlessly. It was really another step toward showing that the Challenger and the Columbia and the whole STS fleet is really, truly moving towards being an operational system.

I think another step towards operations and something that I am particularly interested in – because I worked in it for ten years in Houston, in the Apollo program – is the EVA. EVA offers great promise and I’m glad to see the STS program back int business in EVA and that the group down at Houston, and Story and Don, were really doing such a great job. And that’s going to really be good for the program over both the near term and the long term.

We had a problem after deployment from the Challenger on the second burn of the IUS. There was some kind of an anomaly. As General Abrahamson has said, there is an investigation team in place and working to resolve that. We’re confident that that will be done and we’ll get back on track there also. I guess I went from… from great expectations to the deepest despair, back to semi-elation, and now back to a point of hard, considered work as to what we do from here on out to get this spacecraft where we want it, and operating the way we know we can.

But I would like to note that I was in the room in Houston when we were trying to… we weren’t trying to, we were coordinating all the activities between ourselves, our contractors, SPACECOM and TRW, the Air Force, the Boeing people, and all of the other contractors and people around the country that were involved in the coordination of the activity to carry out the deployment sequence through the two burns of the IUS.

And it worked very well. The decisions were made in real-time between the group of people all around the country. It wasn’t just in that room; it was everywhere and over a period of about three hours things happened in a way that we were able to get the spacecraft separated from the IUS, get the spacecraft under control and move on towards what we need to do to get it to operational. Once we got the spacecraft in an inertial mode and stabilized, the team in place to do that, our contractors, industry teams, SPACECOM and TRW, and the engineers from the Goddard Space Flight Center, have been working constantly since that time to be sure that we understand exactly the situation that we’re in and move towards a series of thruster burns over a period of about two weeks to impart about a thousand-foot-per-second additional velocity to the spacecraft at apogee over a period of about two weeks, at which time we believe we will be… are confident that we  will be at the geosynchronous altitude that we require to operate the system the way that we want to, and at 74 degrees longitude.

We will take our time in doing that. We haven’t decided at this point when we will initiate that activity. We don’t need to hurry. We’ve got the spacecraft in a very safe condition. The orbit is a good orbit; it will stay in that one as long as we need to make the decision to proceed with the burns. We’re using little or no fuel to hold the orbit that we’re in. Our altitude is good and we have plenty of time to analyze the situation and decide what to do next and when to do it. But we do know that we have enough fuel and we have the capability to get there, and we’ll be initiating that sometime whenever our teams have all analyzed it and have decided that we’re ready to go.

And again, congratulations to the STS team and thanks to Abe for a good ride.


WHERE DO WE STAND? WHERE DO WE GO FROM HERE?

Question: Abe, first question is how long you think the repair of the blanket insulation will take. What will it add in the turnaround time? And the second part, it may be glasses time again, but could you give us the schedule for the next mission.

 Abrahamson: I understand that you want to make reservations at the Cape, right? Actually, the repair of the blankets… I was looking at the 103 vehicle last night down at Downey, or… I’m sorry, at Palmdale here, and we’re putting on those blankets. We can put on maybe ten or twelve a day, very easily. So it just won’t add any turnaround time at all. We’ll probably take our time about it though, because we’d like ti understand just exactly what it is that it came off. But it won’t add any time, and then it’s a matter of just a day or two. – Okay, next launch. We’re planning an early-June launch, as I mentioned, and we’re not picking an absolute date at this point in time because we would like to see just how quickly we can turn around the spacecraft here and get it back to Kennedy. And we’re just tentatively targeting about the second week in June at this point… Pardon me?

Question: How about eight?

Abrahamson: Eight. We’re tentatively about the first week in August.

Question: Abe, what about Spacelab? Will the TDRS problem affect that at all now?

Abrahamson: Well, we do have some relay tests decisions to make as we go through the summer, of course. The investigation effort, which is just an accelerated investigation effort by a joint team of NASA and the Air Force on the IUS, will determine whether or not we can quickly find out, number one, what the problem was – and develop a fix that we can have confidence in. Until we do that, we won’t commit another IUS with another TDRS; so that gate we have to get through prior to the time we launch the second TDRS spacecraft.

Now, just in case something goes wrong with that and we can’t make that by the first week in August time frame, we are working on a backup plan; and that backup plan is to use a single TDRS to support the Spacelab mission. And that’s looking favorable, however, we have several things we have to go through with that as well. We have a great number of scientific customers on Spacelab, as well as the European Space Agency. So, once we get this plan fully laid out, and have determined whether or not we indeed need a sufficient number of the science objectives – so they will determine that from a science point of view, as well as a Spacelab checkout point of view, that that’s a satisfactory mission – well, then we’ll go ahead.

Now, from the Space Shuttle viewpoint, we can maintain that September 30 launch; that’s not a problem. The real question is, will we be able to get the science return we’re after. And as I say, that’s more favorable now, as we’re going through that backup plan, even with a single TDRS. But that final decision won’t be made for about a month.

Question: What about a worst case scenario for Spacelab if this second TDRS is not sent up? And this alternate plan doesn’t meet your needs for your various customers? Would you hold the Spacelab for another flight, or what would happen with that?

Abrahamson: That’s a tough decision we’d have to make. And I couldn’t make that alone. I’d have to make it in collaboration with our European partners in the Spacelab program. Their preference at this point, provided we can get an acceptable level of science, is to hold to that September 30 date. If it’s for some reason slipped into the winter period, then the science would be impacted another way. We would not have the right time of the year, and some of the lunar conditions that we want in order, again, to get good science. So, it could be a significance that this happened. We’re doing our best to avoid that.

Question: Is the shuttle’s credibility of being able to put satellites into orbit threatened at all by the mishap? By the problems you’ve had with this?

Abrahamson: I don’t think so. We’ve continued to sign up customers by the way, throughout the time we were on the ground prior to the flight, and even another one during the flight. So, I don’t think so. Now, surely there is – and I don’t want to minimize the problem – there is an honest to goodness problem with the IUS that we have to find and solve. And we’ll do that, and we’ll find it and we’ll solve it.

Remember, most of the payloads, particularly the commercial payloads, go up on PAM-D and PAM-D2, an advanced version of the PAM. At this point in time, the IUS is only going to put up in the near term some very large NASA payloads; those are Ed’s, the TDRS satellites, and for the Department of Defense, some of their large security payloads. So, outside of that rather limited community the IUS problem should not affect the shuttle’s overall system capabilities.

Question: Will the investigating board be able to definitely find the cause of this IUS failure, and if so, when?

Abrahamson: It’s very hard to predict, of course, what the board, when the board will be able to come up with data, because one of the things that we lost was the telemetry on the IUS. But we did get some rather critical items of telemetry that indicated some of the problems that we had prior to the time that the whole anomaly developed. We also got a very exciting picture of the failure itself.

We have a very powerful camera that’s part of the NORAD net that was in New Mexico. And what we’ve seen… we saw the failure. You can see the plume develop on the IUS and develop for about 300 miles, this large plume stick out behind us; and then, at the time of the failure, you can see that the plume pushes off in another direction, and you can see just exactly the timing, and how it went hard over.

So, that’ll be a great help to the investigating board. I think we have a significant amount of information; whether or not we had enough to be able to get right down and find exactly the cause is of course a real challenge. And therefore I can’t predict it.

Question: I gather your doomsday scenario here is not finding the cause of the STS-6 IUS failure and not being able to launch the IUS on STS-8. And you’re needing one TDRS minimum to do the Spacelab with. Is that not correct?

Abrahamson: That was the worst case, but as I’ve indicated we have high confidence we can restore this one, so we think that we do have an optional backup. And, of course, I have a team of people now doing backup scheduling in case the IUS and TDRS flight aimed at the first week in August had to be delayed. So, we’re looking at how it is we can – with minimal impact to our customers – have a way in which we can go up a little later.

Question: Are there any considerations on your part to really look seriously at placing an EVA on flight eight or ten to get more experience on the hardware before committing to Manned Maneuvering Unit ops on eleven?

Abrahamson: We have looked at that and find that the disadvantages outweigh the advantages, and therefore I just had to say that eleven is the right place to do that. One thing that might change that whole scenario would be if, for some reason, we were not able to proceed with the IUS/TDRS flight on eight. That will provide both an opportunity in additional payload weight and capability to do some additional things on the flight. So, those might change then.

Question: Well, that really gets into my second question, Abe. What is your option for flying eight with the Insat payload, and possibly an EVA on eight, if you can’t get the IUS issue resolved? Would you still look to fly the eight crew, with the Insat, in that August timeframe?

Abrahamson: We’re looking at several different alternatives, and we just haven’t made those decisions yet.

Question: On nine, if for some reason the TDRS system doesn’t work itself out, is there any contingency to reconfigure nine to do something else with that shuttle opening?

Abrahamson: No. At this point, all of our emphasis has been on just seeing if we can in fact maintain that schedule for the Spacelab itself. Now, if for some reason we were not able to launch Spacelab on the ninth, or on the September 30 date on that ninth mission, then that opens up a flexible area on which we could do some minor changes for all of the others. But I would remind you that it’s not just a matter of changing the shuttle timeline. The shuttle is getting to be more and more flexible. We also have to have the payloads ready; and there are limits into how much the various customers can either accelerate or accept a delay in their payloads. So, that’s clearly a factor, as well as the shuttle scheduling.


WHAT’S UP FOR THE TDRS NOW?

Question: The satellite correction program – what kind of orbit do you hope to put it in? Will it be the orbit that was planned for it when you’re finished?

Smylie: Yes, sir, we expect to have it in geosynchronous orbit; our location that we desire is 74 degrees to continue our checkout. Actually we have initiated our checkout now. We plan to go geosynchronous.

Question: Given the need to use onboard fuel to correct the TDRS orbit, unless reducing the amount of fuel available for station keeping, by how much will the life time of the spacecraft be reduced?

Smylie: First, at this point we don’t have a TDRS failure, we have a failure to achieve the proper orbit. We have sort of a serendipitous situation concerning the fuel, that the amount of fuel that we have onboard, 1,300 pounds, was there primarily for some very precise station keeping required for the commercial service component of the TDRS program, which actually would have been the fourth satellite to be launched. Back in the fall of last year, that commercial part of the program was eliminated through mutual agreement between ourselves and the contractor.

So, we do not have the requirement for the precise station keeping for the commercial service anymore. And the requirement for the TDRS service for the NASA payloads is much less. So, for the ten-year period that we would design the satellite, we don’t need all that fuel. So, serendipitously we have the fuel available to make this orbit correction.

On the other side of that coin, we could have made a decision to remove that fuel pre-launch, and we left it in there. Somewhat for this reason, that you always have the possibility of a short burn on an upper stage; and it’s good to have fuel available to make that last correction if you need to. We never expected to make this large a correction; but we do have the fuel, so it will not affect the life of the satellite for its intended use at this point. 

As far as future payloads are concerned, when we get the satellite where it belongs, we are in the process of checking it out now, so we are not losing checkout time substantially. If we’re able to launch the second satellite in August, there will be no effect on future payloads.

Question:When will you know when the TDRS burns will be started and how long they will last to restore it to geosync?

Smylie: Well, on the first question, as to when we will start, we won’t start until we’re ready and we won’t be ready till the teams that we have in place at TRW and Goddard have thoroughly analyzed the options for doing this, have understood the strategy for doing it and reviewed it with us and then, not before then, will we start that. That could be sometime within the next week, it might be longer. There is no hurry… we’ll do it when we’re ready.

Question: What is your rough guess, Ed?

Smylie: Well, I don’t even have a rough guess right now, because the people that are working the problem are in California, and in Maryland, and in White Sands, and I’m going to start talking to them about this on Monday to establish exactly what the sequence will be. You know, if I had my druthers, we’d be doing it sometime next week, but I don’t know if it is going to come out that way or not. So I won’t predict right now, because it’s got to be reviewed among all those organizations before we proceed. I think we have in place one of the best groups of attitude control and precaution people in the country working this problem and I want to let them do their work, and then come talk to us about what they think should be done and when… You asked how long the burn would take. The estimates are about two hours per day per apogee for about fourteen days.

Question: Yesterday we were told that TDRS was experiencing in NASA’s language some roll dynamics anomalies. Does that spacecraft in fact continue to experience these problems?

Smylie: We did have some roll dynamics concerns, especially when we came out of the eclipse period. We instituted last evening a new procedure for going through the eclipse, which involved putting pitch and yaw in inertial mode, keeping the Sun sensors on, even though there was no Sun, and keeping the roll on the Sun mode. And we’ve now gone through two eclipses in that mode with great success. We come out within the deadband when we come back into the Sun with no action of the attitude control system at all. So, we think that we have that completely under control now, and so that is not, at this point, a significant problem in terms of the operation we’re doing now. But it is part of the analysis of how we go about doing the translation burns or the apogee burns later. And that will be part of the analysis that the teams are going through now to see how to deal with that.


FROM DREAMS TO REALITY

Question: Can you tell us how the overall performance of the Challenger compares to that of the Columbia, and as a follow up, if there is a favorable comparison, can you say that the shuttle program has truly arrived that you feel confident, that you can build spacecraft, send them into space, bring them back without any particular problem?

Abrahamson: Well, I mentioned the number of anomalies. I think that is a very good indicator; and indeed the Challenger was a much better spacecraft. It was manufactured in a more exacting way and had a higher quality level. And that’s what one expects with the second vehicle as opposed to the first. So I clearly feel that all the indicators are that it is indeed a better spacecraft.

However, I’d like to concentrate on the team. I was asked prior to the lift-off, are we operational? Essentially the same question you had. I believe we will still find, as we go downstream, some minor hardware problems and probably some software problems. There still is a level of maturity that the system has to achieve, and I don’t expect any of them will be serious problems, because I think that we’ve gotten most of the significant bugs out of the system. But there will be some.

Most important thing, and the one that I like to focus on, and the one that I think is a real credit to the Space Shuttle organization, is that the team is ready to find these problems and in stride solve those problems, and make corrections and get the machines back into operation. Now, it cost us a little bit this time. It cost us two and a half months, but that was the price that was worth paying to assure the safety of the astronauts and the vehicle.

Furthermore, it was a price worth paying because we’re going to have a better, more operational program downstream. And we did develop tests and procedures starting way back in the manufacturing process, a little tighter operation there, and the engineering process, and all the way through our flows down to between flight checks at the Cape. So, if you measure operational by the people, I think that at least I’m very confident that we can go ahead. And in the airplane programs and missile programs I’ve been associated with in the past, that’s the best way to measure whether or not you’re operational, because there’s always a problem you have to solve. In fact, if we didn’t have any problems to solve, this would be boring business.

Question: You had a spectacular glamorous flight. The EVA was just spectacular. What are you going to give us for an encore in terms of very specific things in terms of EVA? And what have you that the public can look forward to?

PAO: Did you plant that question, Abe?

Abrahamson: Well, the real objective of the program is not to have a series of circuses, you know that. But we like to do things that are exciting for all of us and that lead to the operational capability of the system. Let me try to put in context what I think is going to be an exciting year.

On the next flight, the seventh, of course we’ll put up two communications satellites. But following in the context of the EVA and getting ready to demonstrate our ability to repair satellites, Sally Ride, our first lady astronaut, will operate our Canadian arm. What she’ll do is she’ll take a German payload… now notice that nice international flavor to that. She’ll take a German payload, an exciting one called SPAS, and I think I commented on that last time. And she’ll put it outboard with the Canadian arm, and it’ll fly and keep formation with the shuttle, and we’ll kind of move around and do that. But we’ll really test our ability to reach out with this Canadian arm, grapple the satellite, alright, with different rates and small errors associated with it and bring it back and put it in the bay. And we think that’s a very important thing to demonstrate.

Next, in the eleventh flight downstream, we’ll demonstrate the Manned Maneuvering Unit. And at that point our astronauts will not have to be tied to the tethers, but they’ll go scooting around outside the bay in order to demonstrate maneuverability in the fact that we can in fact control the movement and work in the space around the shuttle itself.

And, of course, all of this is a step by step process to work up to the thirteenth flight, which is scheduled late in the spring of ’84; and that’s when we’ll go out and we’ll repair a wounded satellite, the Solar Max satellite.

And I think that’s a whole series of things that have got to catch the public imagination. It certainly catches ours. But the important thing is we’re approaching it in a step by step conservative fashion to ensure that we’ll have the capability to do it, and to do it well. And that’s the kind of sequence as we go through the next year. Now, in addition, of course, we’re putting up some very exciting payloads and having a series of important scientific experiments as well. And I don’t want to minimize those.

Question: And just one more question about STS-7. In view of the success of the EVA and your own expressed wish to press on with this activity, are you likely to introduce an EVA on that mission?

Abrahamson: No, because we have a very full mission associated with the other objectives. And some of those objectives, of course, as I indicated are part of this plan to develop this high confidence that we can indeed make a satellite repair on the 13th mission. So, it’s important to us to have some stability in our planning and we won’t, we will not introduce an additional EVA session on that particular one.

Question: What about future shuttle landings? Will they continue here at Edwards? Will they move to Florida, or elsewhere?

Abrahamson: Our next landing, God willing that we have some nice weather in Florida, we’re planning at the Cape. Now, there will be some limits, and we have to have something that we can accept; we don’t want a crosswind more than around ten to fifteen knots, and that final decision has yet to be made. And in the June timeframe we don’t think that’ll be a problem. However, we are concerned about the weather at that point. There are quite a few thunderstorms at the Cape, and we have to be able to predict a full three hours or so prior to the landing. So, we’ll look very carefully at what the local weather looks like primarily from a thunderstorm viewpoint; we don’t want to land through any thunderstorms. But the plan is to go to the Cape.

Question: Routinely, that is? Edwards will no longer be the primary landing site?

Abrahamson: No, we’ll alternate back and forth. The eighth flight, providing we do go ahead as scheduled, will be a night landing. And the first time we do this at night, we’d like to have all the room that’s around here; and provided the lake finally becomes a dry lake again, like it ought to be, well, then we’ll come back here on the eighth flight. So, it will alternate back and forth depending on some of our objectives and some of our limits for a period of time. But our objective is to get routinely to the Cape as quickly as possible.

Question: Philosophically, now that you have demonstrated the spectacular success  of the Challenger, does this give you a level of confidence to plan things that before this mission you didn’t have the confidence to plan looking down beyond ‘84? And if so, what are some of those things that you can now realistically expect to accomplish that before this you couldn’t?

Abrahamson: I think there’s a better way to put that: We have had plans which step up and take on more difficult challenges as we go on through that. And what’s happening is that with each success that confirms that indeed our plans are good plans. So, what we had happen this particular time hasn’t said, “Okay, now we have a whole new horizon opened up.” I think, much better is that we had both some dreamers and planners in the agency, and those dreamers and planners are finding that we’re moving a little ways away from the dreams into the reality of the planned.

(STS-6 post-landing press conference transcript, Apr. 9, 1983 – edited)
« Last Edit: 11/10/2013 02:52 am by Ares67 »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #652 on: 11/10/2013 02:28 am »
April 16: CHALLENGER WHEELS IN FOR SPRING CLEANING
Challenger, described as the "cleanest" spacecraft to return from space, arrived at the Kennedy Space Center at 12:45 p.m. EST, riding atop a 747 jet. The mated pair of planes approached the Space Center from the south, flew over the runway once and circled back over the Indian River. On April 14 Challenger was flown to Kelly AFB, Texas, on the first leg of her return to Kennedy. After a one-day stopover the SCA/OV-099 combo left for Florida. At KSC, about 2,000 tourists and KSC workers and their families saw the landing from close-up. Challenger was then demated and towed to the Orbiter Processing Facility. NASA officials said preparations for the seventh Shuttle mission had already begun.

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #653 on: 11/10/2013 02:33 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #654 on: 11/10/2013 02:37 am »

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #655 on: 11/10/2013 02:39 am »
“The vehicle looks like we just rolled out of the OPF at Kennedy,” KSC Ground Operations Manager Jim Harrington had said immediately after touchdown at Edwards AFB a week ago. “It’s just a clean ship. Compared to what we’ve seen in the past, it’s probably a lot cleaner than any of the Columbia flights.” NASA spokesman Mark Hess today said Challenger not only was cleaner in appearance, but also encountered fewer problems than was the case with Columbia.

One of the few flight anomalies included a random propellant leakage of an RCS thruster during the mission, and this indicated drainage of the No. 2 manifold before the ferry flight back to KSC. It took some six hours to unload the six gallons (22.7 liters) of monomethyl hydrazine and nitrogen tetroxide, but a 12-15 hour deservicing operation on the whole manifold area was accomplished to enable extensive leak checks on the system. It was thought that KSC ground-based quick-disconnect equipment had damaged the onboard unit, but evaluation found no traces of hardware damage to the connection. The investigations will continue back at the Cape.

Tile damage to OV-099 is minimal but noticeable. Three Advanced Flexible Reusable Surface Insulation thermal protection blankets were blown loose, one lost completely, on the left side OMS pod, and three were also lost from the right-side OMS as well. Some of the damage on the OMS pods is thought to have been caused by encountering Max-Q during launch.

The AFRSI thermal blanketing “consisted of silica tile material sandwiched between sewn composite quilted fabric which was much lighter than the Low-temperature Reusable Surface Insulation tiles used on other sections of the orbiter’s airframe,” Ben Evans describes in his book Space Shuttle Challenger – Ten Journeys into the Unknown. “Challenger’s AFRSI damage ranged from missing outermost sheets and insulation to broken stitches and, in the severest cases, was even attributed to ‘some type of undetermined flow phenomena’ during reentry.” In addition, about five square inches of LRSI on the Challenger’s body flap was eroded. As with the Columbia flights, there was some discoloration of the white-tile LRSI surface of Challenger, though not so marked as on Columbia.

“Brake, axle and wheel damage suffered by Columbia at the end of STS-5 had already led to the incorporation of successful ‘saddle’ modifications,” wrote Ben Evans in 2007. “However, the Challenger’s landing was not as perfect as expected. During post-landing disassembly, six cracks were detected on three stators in her right-hand inboard brake. Subsequent investigation revealed an undersized machining template had caused expansion slots in the stator disks to be produced ‘undersized’; it was possible, NASA’s report said, that similar problems had arisen on STS-5, although on that mission the stators were so ruined that it was difficult to prove.”

Planning calls for a launch of STS-7 on June 9, which would mean a record vehicle turnaround at KSC; the STS-8 launch is scheduled for early August. Last week, Associate Administrator for Spaceflight Lt. General James Abrahamson said AFRSI installation on orbiter 103, the Discovery, is now progressing at the rate of ten or twelve each day, and that he expects the repair of those on Challenger will add little, if any, time on the tight turnaround process at the Cape. Also, a possible quick-fix remedy is considered for STS-7, before a more permanent fix with new blankets for STS-8.

(Today, Apr. 18, 1983; JSC Space News Roundup, Apr. 13, 1983; The Tribune, Apr. 20, 1983; Melvyn Smith, “An Illustrated History of Space Shuttle,” Haynes Publishing Group, 1985; Ben Evans, “Space Shuttle Challenger,” Springer/Praxis 2007 - edited)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #656 on: 11/10/2013 02:41 am »
April 22: NO MORE PRESS CONFERENCES
At Johnson Space Center today the STS-6 astronauts held their post-flight crew conference – a task they seemed not to like very much, considering Mission Specialist Donald Peterson’s response to Today’s Frank Yosenda, who had asked, “Following this flight, what essentially do you think you’re going to do in terms of plans, and has the flight changed your life in any way, or changed your plans in any way?”

“I don’t plan to have any more press conferences,” quipped Peterson. “No, I don’t know. I think we’re too soon after the flight for me to try to answer that. We’re still in the midst of trying to get everybody on the Center debriefed from what we found, from what we’ve learned. And at some point in time I think most of us are really looking forward to talking to the engineers, and the flight controllers, and the people on the ground, and finding out what they learned, because we’ve really done very little of that.” He added, “And I’d like to get a couple of weeks off, and I understand we have some public appearances to do; and maybe after that we’ll start looking at what’s going to happen later.”

Mission Specialist Story Musgrave said, “I don’t think it’s changed my life too significantly. It’s brought to fruition something that I’ve been working very hard on for at least sixteen years, and I’m just looking forward to going again as soon as I can.”

“I think it certainly was a great experience,” responded Pilot Karol Bobko. “I’m looking forward to going back. I said at the return to Ellington that I thought I had imagined everything that could be seen in orbit by listening to people who had flown over the time, as if I had been there; but that’s certainly not true. It’s beautiful, it’s great. I’m hoping to be able to go back sometime.”

“And I essentially echo Don’s comments,” Challenger Commander Paul Weitz added. “Right now, we’re taking one day at a time, waiting to get all the debriefings behind us, and to be able to direct our attention back to contributing to the program.” (STS-6 post-flight crew conference – edited)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #657 on: 11/10/2013 02:51 am »
April 27: OPF INCIDENT INVESTIGATION
Two men who were in the Orbiter Processing Facility at Kennedy Space Center during a leak of highly toxic hydrazine rocket fuel on April 17 returned to a Titusville, Florida, hospital suffering from respiratory problems. Both men – photographer Alex Bosmeny, 61, and firefighter Vernon Woodard, 32 – said on April 26 that no alarm had sounded after the spill, thereby increasing their exposure to the harmful gas.

KSC spokesman Hugh Harris said it was possible the high bay, where the leak occurred, was cleared by word of mouth rather than by an announcement over the public address system. He also said that there was as yet no evidence that the two men had been injured by hydrazine. Harris said, further, that a KSC committee had been formed to investigate the incident. Area Occupational Safety and Health Administration Director Bill Demery said that OSHA would investigate as well. (Today, Apr. 27, 1983)


April 29: TEST FIRINGS PLANNED FOR TDRS-A
Officials plan to conduct two test firings of the thrusters on the Tracking and Data Relay Satellite (TDRS-A) before starting maneuvers designed to boost the satellite into its proper orbit. Deployed from the orbiter Challenger during STS-6 TDRS-A failed to achieve its planned orbit of 22,300 miles due to an unidentified problem with its Inertial Upper Stage booster. Some damage was done to two of the four roll thrusters on the satellite, and both have been shut down as a precaution against possible fuel leakage.

No date for either of the test firings has been set, said Ronald Browning, TDRSS Project Manager at the Goddard Space Flight Center. Browning said NASA and TRW officials are still working out the details for maneuvers designed to change the TDRS-A elliptical orbit to a circular one. He said it is hoped the first firing can be conducted the first week of May, and the second four or five days later.

The test firings will be made to check out the mathematical models which are being developed for changing the TDRS-A orbit. Basically, Browning said, the firings will check out the spacecraft’s attitude control system, with special attention being paid to thermal characteristics and fuel utilization. The spacecraft has been using about one-half pound of hydrazine fuel each day in its orbit of 22,000 by 13,600 statute miles. The maneuvers to correct the orbit are expected to take several weeks.

During the test firings, the first maneuver will last for about twenty minutes, and the second slightly longer. Telemetry from the first firing will be reviewed by NASA and TRW officials to see if the results are consistent with expectations before a go-ahead is given for the second firing, Browning said. The number of thrusters to be used during the test firings has not been determined as yet, he said. Several different modes are under consideration.

Engineers are also trying to assess damage to the spacecraft. Besides the roll thruster damage, they are also examining the temperature profile at the base of the satellite, including both the roll and pitch thrusters. Browning said temperatures have been running warm in those areas, but the problem is seen as manageable. There is some speculation that some of the thermal insulation has been degraded in some way, but because of limited data no solid conclusions have been drawn on what might be causing the temperature fluctuations, Browning said. (JSC Space News Roundup, Apr. 29, 1983)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #658 on: 11/10/2013 02:54 am »
May 5: TDRS-A TEST FIRINGS A SUCCESS – BEGGS “SOMEWHAT PESSIMISTIC” ABOUT TDRS-B
On May 2, a 41.5-minute test firing of NASA's sophisticated new Tracking and Data Relay Satellite TDRS-A indicated to project engineers the spacecraft could be successfully maneuvered to a proper geosynchronous orbit. Today, the second, 43-minute burn also was successfully completed, although there were reports of higher than desirable temperatures in one of the thrusters.

Meanwhile, NASA Administrator James Beggs said the space agency had not made a final decision on whether to launch the second satellite, TDRS-B, aboard the STS-8 mission in August, but that he is "somewhat pessimistic" that it can be included on the mission because of the time needed to correct the problem with the Inertial Upper Stage, which caused the TDRS-A to go into improper orbit. (Today, May 3, 1983; Defense Daily, May 5, 1983 – edited and supplemented)


May 13: TDRS CORRECTION BURNS BEGIN
With two test firings of the thrusters on the first Tracking and Data Relay Satellite successfully behind them, the recovery teams working on the errant spacecraft have begun a second phase of burns designed to loft TDRS-A into a higher orbit, and eventually send it to the planned geosynchronous position in about five weeks.

At Roundup press time, apogee burns about every 18 hours were to have begun earlier this week in which the spacecraft’s orbit will be refined to 22,000 by 18,000 statute miles. This will require about 23 hours of burn time, or about a 20-day effort, according to TDRSS Program Manager Robert Aller. The third phase of TDRS-A correction will be a 17-hour series of burns designed to circularize the orbit at the present 22,000 statute mile apogee. At that point, ground controllers will refine to the desired 22,300 mile geosynchronous orbit.

Controllers are first shooting for a raised perigee of 17 to 18,000 miles to allow the sensors aboard TDRS-A to go into a Sun-Earth inertial mode. At the higher altitudes, the spacecraft’s Earth sensor will be able to properly lock on the Earth and use it for reference, something which is not possible now because the Earth looks too large to the sensors in the lower orbit. TDRS-A is now using the Sun for its reference.

The two firings were about 40 minutes each, with the longest being 43 minutes. Technicians had planned longer burns in each case, but during the first firing a roll thruster developed high temperatures and the burn was curtailed 18.5 minutes early. During the second thruster firing, May 5, a 43-minute burn was completed before a yaw thruster also developed a higher than desirable temperature. During the second firing, temperatures in the first roll thruster were acceptable; an indication that technicians understand the thermal problem and that corrections can be worked out. They hope to initiate a series of one hour burns during the actual correction phase underway.

 In both cases, the thrusters were operating correctly as commanded by on-board equipment. However, the firing rate of both thrusters was such that high temperatures developed. Cooling of the thrusters comes from hydrazine fuel, thus the fewer times the thrusters are fired the greater the chance of higher temperatures. Program officials believe the entire series of thruster firings over the next month or so will consume about 800 pounds of hydrazine, leaving an ample amount for attitude control of the TDRS-A over its ten-year lifetime. (JSC Space News Roundup, May 13, 1983)

Offline Ares67

  • Senior Member
  • *****
  • Posts: 13494
  • Oliver
  • Remscheid, Germany
  • Liked: 74
  • Likes Given: 28
Re: Challenger STS-6 – A Walk into History
« Reply #659 on: 11/10/2013 03:01 am »
May 27: SECOND TDRS OFFICIALLY DELETED FROM STS-8 MANIFEST
The second in a series of Tracking and Data Relay Satellites that had been scheduled for launch aboard orbiter Challenger in August 1983 has been officially deleted from the eighth shuttle flight cargo list. The decision by NASA program managers to remove TDRS-B from the STS-8 cargo was based on the failure of the Inertial Upper Stage solid rocket booster to propel the first TDRS to geosynchronous altitude after deployment from Challenger on April 4 during the STS-6 mission. Reasons for the IUS anomaly and final corrective actions are under continuing evaluation by a joint U.S. Air Force and NASA Anomaly Investigation Board.

Attempts are underway to gradually boost TDRS-A to the needed 22,300 miles circular orbit using the satellite’s small attitude thrusters, firing on commands sent by the TDRS ground station at White Sands, New Mexico. This effort has been highly successful to date and the TDRS orbit perigee has been raised to 18,559 statute miles as of May 27, 1983. This leaves 3,675 miles of perigee altitude and 57 miles of apogee altitude remaining to place the satellite in its originally intended geosynchronous orbit.

A Payload Deployment and Retrieval System Test Article, originally planned to be carried aboard Challenger on STS-11, will be loaded on STS-8 in place of TDRS-B. PDRSTA is a 15x16-foot, 8,500 pound aluminum and steel structure fitted with four grapple fixtures. The test article simulates a large-mass payload for flight testing the Remote Manipulator System, or robot arm. The purpose of the tests is to evaluate elbow, wrist and shoulder joint reaction to higher loads and to gain crew experience in operating the 50-foot-long Canadian-built mechanical arm.

Unaffected by STS-8 cargo changes is the Indian National Satellite 1, a communications and meteorological geosynchronous satellite being carried by Challenger for the Indian Department of Space. Insat-1 will be boosted from Challenger’s 174-nautical mile orbit to geosynchronous altitude by a Payload Assist Module (PAM-D), the type which successfully boosted a Canadian communications satellite and a Satellite Business System payload from STS-5 last November and will be used again on STS-7. (Terry White, JSC NASA News Release No. 83-020, May 27, 1983; JSC Space News Roundup, June 6, 1983 – edited)


June 13: CONTROL MECHANISM FAILURE BLAMED FOR IUS PROBLEMS
A mechanical failure in the second stage control mechanism on an Air Force-developed upper-stage rocket caused a sophisticated communication satellite to go astray after launch from the Space Shuttle Challenger in April, said Air Force Space Division spokesman Col. Jeff Baker. The Los Angeles-based Col. Baker said work was already under way to assure the problem does not recur on similar Inertial Upper Stage rockets under construction for future flights. "There have been reports that everything is on hold for the IUS, and that's not true," Baker said. (Today, June 14, 1983)


NOZZLE GIMBAL LIKELY CULPRIT ON IUS FAILURE
Collapse of the nozzle gimbal mechanism on the Inertial Upper Stage is the most likely cause of the poor thruster firing that sent the first Tracking and Data Relay Satellite into a low elliptical orbit during STS-6 in April. Those are the findings released by the joint Air Force/NASA Anomaly Investigation Board after three months of study. “Failure of the gimbal system used on the IUS solid rocket motor caused the nozzle to be mechanically jammed in an offset position,” the report said. “The actuators were unable to overcome the high mechanical forces caused by the jammed nozzle while the motor was thrusting.”

The failure occurred at approximately 83 seconds into the SRM-2 burn. At that point, the motor, which had operated nominally, had an uncommanded rocket motor nozzle position change in both pitch and yaw. This uncommanded deflection resulted in the uncontrolled tumble of the IUS/TDRS stack at a rate of approximately 30 rpm. “No net increase in orbital velocity occurred after tumbling started,” the report said, “even though SRM-2 continued to burn for the planned nominal time of approximately 105 seconds.” The pitch and yaw actuators, which had responded to commands before the gimbal mechanism apparently collapsed at 83 seconds, did not respond to commands from that point until after the burn was completed.

The Investigation Board identified four potential sources of the nozzle gimbal mechanical failure: a breakdown of thermal protection in the flexible seal around the nozzle; long-term seal leakage; quality or manufacturing problems; or environments to which the assembly was exposed. The Air Force said a decision about the near-term launch schedule of the IUS is expected this fall. NASA is tentatively planning the next IUS/Shuttle launch for STS-12 in March 1984. The Air Force’s IUS Program Office has identified three means to resolving the problem, the Air Force said. They include nozzle component testing, non-destructive testing of motor nozzles leading up to ground test firings, and a rebuild of the nozzle using stringent quality control. (JSC Space News Roundup, Aug. 5, 1983 – edited)


June 29: BURN, BABY, BURN – TDRS-A IS NOW ON STATION
After 58 days of delicate maneuvers, a NASA-industry team succeeded in placing the first Tracking and Data Relay Satellite into its proper geosynchronous orbit June 29, using what a TRW official called “the world’s smallest orbital injection engines.”

When TDRS-A finally separated from a malfunctioning booster and stabilized itself April 5 after undergoing a 30-rpm tumble, engineers were still faced with one of the most demanding challenges in the history of satellite operations. TDRS-A was in a lopsided 13,574 by 21,970 statute mile orbit, almost 9,000 miles shy of its planned circular orbit. Over the next 58 days, experts from NASA, SPACECOM and TRW executed a series of burns using tiny one-pound stabilization thrusters, with nozzles about the size of a thimble, to boost the 5,000-pound spacecraft some 8,662 miles farther into space – an exercise never before attempted.

Thruster firings of various durations began in May, with the last coming June 29 on the “Burn, baby, burn” command of NASA Administrator James Beggs during ceremonies in the TDRS support room at Goddard Space Flight Center in Greenbelt, Maryland, to mark the achievement. The 44 hours of firings made up for the loss of about 15,000 pounds of thrust during the failed orbital injection sequence during the morning hours of April 5.

With the activation of an Earth-lock mode on TDRS and the successful beginning of a communications system checkout coming up in mid-July, the satellite is nearing readiness for tests with Landsat 4 in late July and with the orbiter Challenger during STS-8 in August. A series of four Detailed Test Objectives and flight tests objectives will be performed with the TDRS on Flight Days Three, Four and Five during the mission, although regular air-to-ground communication through the satellite will commence as soon as Challenger passes Dakar on the first orbit.

The orbiter will communicate with TDRS on the S- and Ku-bands, and coverage will be about 40 minutes during each rev, in addition to regular ground station communication elsewhere around the globe. Coverage through TDRS begins at about the mid-Pacific Ocean region and ends about where Indian Ocean Station coverage begins on the east coast of Africa.

“This has been a long, hard siege, but it paid off. The effort of the TDRSS team represents some of the best in American skills and ingenuity,” James Beggs said. “It is, I think, an example for the world, certainly an example for the country, that we are able to do this in full view of the world. We don’t hide anything. We’re telling them exactly what we’re going to do. We tell them about our troubles, and we let them know every stage of the way. ”

Firings during the correction procedure typically used six thrusters. Four were used to control stability, while two were used to push the spacecraft. Goddard Space Flight Center Director Noel W. Hinners said his calculations showed the thrusters got “about 85 miles per gallon,” and he noted they were “made in the U.S.A.” by TRW, which also built the spacecraft.

TDRS-A is now in a 22,234 by 22,237 statute-mile orbit with  a period of 23 hours and 56 minutes and an inclination of .02 degrees. A final trim on the orbit will be made during the planned drift movement from 67 degrees west longitude to the permanent location at 41 degrees west longitude this fall.

After the test with Landsat 4 and STS-8, the satellite will provide major support to the STS-9 Spacelab mission in October. It is the first of three satellites to make up the TDRSS network. The second TDRS, originally scheduled for launch on STS-8, has been postponed pending correction of the problem with the Inertial Upper Stage booster. If the problem can be corrected in time, NASA tentatively plans to launch TDRS-B on STS-12 in March 1984. The second satellite will be positioned at 171 degrees west longitude over the Pacific. The third TDRS satellite, an in-orbit spare, will be located at 79 degrees west longitude over the Pacific off the coast of South America. (JSC Space News Roundup, July 22, 1983 – edited and supplemented)

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1