The X-37B: Exploring expanded capabilities for ISS missions

[vulture4]

OSP was intended to provide manned access to ISS initially as a backup to Shuttle and later as a replacement. Boeing and Orbital were each asked to provide two proposals for OSP, a winged vehicle and a capsule. Boeing proposed a capsule somewhat similar to the CST and a winged vehicle based on the X-37 although larger.  Orbital proposed a similar capsule and a winged vehicle called Prometheus. The OSP program was cancelled in favor of Constellation but before this occurred NASA indicated a preference for the capsule because it had a larger internal volume. This may have influenced Boeing to propose the capsule for the CCDev program. Orbital again proposed the Prometheus for CCDev but was not funded, partly because it had only four seats, although this clearly met the minimum requirement. The capsules held seven. Sierra Nevada's lifting body held six and was based on a side-by-side seating configuration with liked by the astronauts with two front seats directly behind a windshield, and still received less funding than the Dragon and CST.

The X-37C could carry six and had about the same internal volume as the Dreamchaser. The round pressurized cabin would have been easier to fabricate but was longer and thinner, making it necessary for the six crew to sit single file, and difficult to put even one crewman behind a traditional pilot's canopy. Of course it can land perfectly well on autopilot or with the pilot flying by video camera but this would not go over well. I think Boeing simply saw that NASA was more likely to choose a seven-seat capsule design, and that it would be easier and less expensive to build.

I still feel the wing-and-fuselage designs are better aerodynamically than lifting bodies for any given landing mass and volume. Lifting bodies are very difficult to land because of their high drag and low lift and require very high touchdown speeds. As size and mass increase, landing a lifting body in gliding flight becomes impossible, and anything significantly heavier than the Dreamchaser would have to use a parachute, rockets or some similar method to support its weight during landing, leaving it with little or no advantage over a capsule. In contrast, a winged spacecraft can land at a mass of 100 tons or more. This was why wings were chosen for the Shuttle after a decade of work with lifting bodies.

[QuantumG]

The OSP program was    cancelled in favor of Constellation

OSP was cancelled for a "streamlined" program to make the Crew Exploration Vehicle and took at lot of OSP with it.. but so did Constellation. Both changes slowed the program and left devastation, but the ultimate result of the OSP-capsule proposals was Orion. Ultimate so far anyway, who knows what the international effort will do to it.

An elephant is a mouse built to government specifications.

[vulture4]

OSP was cancelled for a "streamlined" program to make the Crew Exploration Vehicle and took at lot of OSP with it.. but so did Constellation. Both changes slowed the program and left devastation, but the ultimate result of the OSP-capsule proposals was Orion.

From a programmatic point I agree with your evolution. But OSP was most emphatically a program to provide human access to LEO only, as thre CAIB recommended. Constellation at first abandoned LEO in an attempt to recapture the glory of Apollo, then added it as a secondary task for which it was poorly suited. It wasn't the changes that left devastation, it was the lack of a practical goal.

CCDev is very much a return to the goals, strategies, and vehicle designs of OSP, with  the major changes being the addition of SpaceX and Sierra Nevada and the reduced level of NASA oversight.

[QuantumG]

From a programmatic point I agree with your evolution. But OSP was most emphatically a program to provide human access to LEO only, as thre CAIB recommended.

There was no real distinction made between LEO and beyond back then.. a capsule is a capsule. They had to make up some 6-month capsule mission fiction in order to justify Orion and then they did a poor job of it anyway.

Constellation at first abandoned LEO in an attempt to recapture the glory of Apollo, then added it as a secondary task for which it was poorly suited.

There ya go again... you do understand the CEV existed before Constellation right?

It wasn't the changes that left devastation, it was the lack of a practical goal.

No, it was the changes. The lack of any goal is just the reason for the continual changes and non-commitment.

CCDev is very much a return to the goals, strategies, and vehicle designs of OSP, with  the major changes being the addition of SpaceX and Sierra Nevada and the reduced level of NASA oversight.

and there's still no agreement on goals. Is it building an industry? Or not? What for? Is it supposed to save money? Why? Why not? Ask 3 congressional staffers and you'll get 5 answers.

[Patchouli]

OSP was intended to provide manned access to ISS initially as a backup to Shuttle and later as a replacement. Boeing and Orbital were each asked to provide two proposals for OSP, a winged vehicle and a capsule. Boeing proposed a capsule somewhat similar to the CST and a winged vehicle based on the X-37 although larger.  Orbital proposed a similar capsule and a winged vehicle called Prometheus. The OSP program was cancelled in favor of Constellation but before this occurred NASA indicated a preference for the capsule because it had a larger internal volume. This may have influenced Boeing to propose the capsule for the CCDev program. Orbital again proposed the Prometheus for CCDev but was not funded, partly because it had only four seats, although this clearly met the minimum requirement. The capsules held seven. Sierra Nevada's lifting body held six and was based on a side-by-side seating configuration with liked by the astronauts with two front seats directly behind a windshield, and still received less funding than the Dragon and CST.

The X-37C could carry six and had about the same internal volume as the Dreamchaser. The round pressurized cabin would have been easier to fabricate but was longer and thinner, making it necessary for the six crew to sit single file, and difficult to put even one crewman behind a traditional pilot's canopy. Of course it can land perfectly well on autopilot or with the pilot flying by video camera but this would not go over well. I think Boeing simply saw that NASA was more likely to choose a seven-seat capsule design, and that it would be easier and less expensive to build.

I still feel the wing-and-fuselage designs are better aerodynamically than lifting bodies for any given landing mass and volume. Lifting bodies are very difficult to land because of their high drag and low lift and require very high touchdown speeds. As size and mass increase, landing a lifting body in gliding flight becomes impossible, and anything significantly heavier than the Dreamchaser would have to use a parachute, rockets or some similar method to support its weight during landing, leaving it with little or no advantage over a capsule. In contrast, a winged spacecraft can land at a mass of 100 tons or more. This was why wings were chosen for the Shuttle after a decade of work with lifting bodies.

The X-33 and Venture star were lifting body designs.

The wing and tube design for the orbiter was more well understood and could borrow a lot of research from the the X-15 and Dynasoar programs.
Orion having an Apollo shape despite it being a some what inefficient shape was for the same reasons.

There are better shapes see Spacex's and Blue Origin's capsules but these come with greater risk.

Though wings do offer better glide then a lifting body.

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the STS orbiter OML.
It's construction was to be much more conventional too.

[go4mars]

There are better shapes see Spacex's and Blue Origin's capsules but these come with greater risk.

How do you figure the "greater risk" part?

[Lar]

There are better shapes see Spacex's and Blue Origin's capsules but these come with greater risk.

How do you figure the "greater risk" part?

Maybe because those shapes haven't had as much flight experience?

Just a guess/attempt to read Patchouli's mind...

[Elmar Moelzer]

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the STS orbiter OML.
It's construction was to be much more conventional too.

I thought the same. Some people say that NASA deliberately went for the most ambitious of the proposals. The one with the most new technology in it. Didnt learn from the shuttle...

[Star One]

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the STS orbiter OML.
It's construction was to be much more conventional too.

I thought the same. Some people say that NASA deliberately went for the most ambitious of the proposals. The one with the most new technology in it. Didnt learn from the shuttle...

That seems a curious decision to make, why not go the more tried and tested route?

[Jim]

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the
I thought the same. Some people say that NASA deliberately went for the most ambitious of the proposals. The one with the most new technology in it. Didnt learn from the shuttle...

Typical of a NASA basher, you are talking out of both sides of your mouth.   

You said the shuttle was too great of a leap and should not have been an operational system but a technology development program.  X-33 is exactly what NASA should be doing, it was a technology development program. 

[Elmar Moelzer]

You said the shuttle was too great of a leap and should not have been an operational system but a technology development program.  X-33 is exactly what NASA should be doing, it was a technology development program. 

So was the X33, if dear sir had bothered to read my full post. The X-33 Venture star was the most ambitious of all proposals.

[HMXHMX]

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the
I thought the same. Some people say that NASA deliberately went for the most ambitious of the proposals. The one with the most new technology in it. Didnt learn from the shuttle...

Typical of a NASA basher, you are talking out of both sides of your mouth.   

You said the shuttle was too great of a leap and should not have been an operational system but a technology development program.  X-33 is exactly what NASA should be doing, it was a technology development program. 

Jim, the lead up to the X-33 program was focused more on the demonstration of a viable high flight rate CONOPS than generic technology development.  While there was a desire (and need) for technology development to both support that aim and the flight rate improvement, for many of those of us involved technology (as NASA usually uses the term) wasn't the prime driver.  (In fact, I lost the argument that a high mass fraction demonstration for SSTO had to be a primary component of DC-X along with the operability demo.)

Further, Gary Payton specifically told me that as Source Selection Authority he chose the most ambitious of the proposals (this was also echoed at the public announcement, though I don't recall if Gary or Dan Golden said it).  Since I regard Gary as a friend, it pained me to have to publicly disagree with his management of the X-33 in front of a Congressional committee a short while afterwards – he and I being the only two witnesses.  I still think selecting the LM proposal was  a serious error of judgement.  And while I personally promoted the MDAC VTOL approach, I would have been much happier to see Rockwell win (with a very fine proposal, I might add) in place of LM.

(I hasten to add that "technology" is so generic a word in our business as to be almost meaningless.  I wanted to see development and test progress on a number of fronts, but felt that propulsion (a major focus of X-33's efforts) need not be among them.  The RL-10 used for DC-X and even the SSME of the day would have been perfectly acceptable to employ for a near SSTO demonstrator that could have flown on a weekly basis, for example.)

[Elmar Moelzer]

Jim, the lead up to the X-33 program was focused more on the demonstration of a viable high flight rate CONOPS than generic technology development.  While there was a desire (and need) for technology development to both support that aim and the flight rate improvement, for many of those of us involved technology (as NASA usually uses the term) wasn't the prime driver.  (In fact, I lost the argument that a high mass fraction demonstration for SSTO had to be a primary component of DC-X along with the operability demo.)

Further, Gary Payton specifically told me that as Source Selection Authority he chose the most ambitious of the proposals (this was also echoed at the public announcement, though I don't recall if Gary or Dan Golden said it).  Since I regard Gary as a friend, it pained me to have to publicly disagree with his management of the X-33 in front of a Congressional committee a short while afterwards – he and I being the only two witnesses.  I still think selecting the LM proposal was  a serious error of judgement.  And while I personally promoted the MDAC VTOL approach, I would have been much happier to see Rockwell win (with a very fine proposal, I might add) in place of LM.

(I hasten to add that "technology" is so generic a word in our business as to be almost meaningless.  I wanted to see development and test progress on a number of fronts, but felt that propulsion (a major focus of X-33's efforts) need not be among them.  The RL-10 used for DC-X and even the SSME of the day would have been perfectly acceptable to employ for a near SSTO demonstrator that could have flown on a weekly basis, for example.)

Glad to read a first hand account of this, Gary!

[vulture4]

The goals of OSP and CC (for NASA) are quite similar and for Boeing the design is similar as well, but IMO SpaceX has integrated human launch with ISS cargo and booster development and appears capable of reducing costs compared with the original OSP concept of sticking with the EELVs. "Commercial" is still largely government funded but provides greater flexibility and less government oversight in both development and operations.

[vulture4]

The RL-10 used for DC-X and even the SSME of the day would have been perfectly acceptable to employ for a near SSTO demonstrator that could have flown on a weekly basis, for example.)

Was there ever a near SSTO design with conventional engines? Why do you think SSTO capability was so critical? Wouldn't it require an impractically small payload mass fraction? I heard when X-33 was cancelled that one reason was the conclusion that the planned operational derivative of the design could not achieve SSTO. Others said that flying the prototype as a suborbital would still provide useful information.

[HMXHMX]

The RL-10 used for DC-X and even the SSME of the day would have been perfectly acceptable to employ for a near SSTO demonstrator that could have flown on a weekly basis, for example.)

Was there ever a near SSTO design with conventional engines? Why do you think SSTO capability was so critical? Wouldn't it require an impractically small payload mass fraction? I heard when X-33 was cancelled that one reason was the conclusion that the planned operational derivative of the design could not achieve SSTO. Others said that flying the prototype as a suborbital would still provide useful information.

We'd be well off topic if I replied in detail, except to say "yes" to your first question, there have been concept designs.  And X-33 was never configured or expected to be orbital, only suborbital.  The rest of the conversation should be in another thread, probably.

[Falcon H]

Wow it sounds like dream chaser might get some competition.

[Lar]

Glad to read a first hand account of this, Gary!

Ditto... just another reason why NSF is awesome.

I have to agree with the assessment that going for the most advanced vehicle tech may have been a mistake if the key deliverable was rapid/cheap reusability demonstration.

[Patchouli]

There are better shapes see Spacex's and Blue Origin's capsules but these come with greater risk.

How do you figure the "greater risk" part?

Maybe because those shapes haven't had as much flight experience?

Just a guess/attempt to read Patchouli's mind...

The lack of flight experience is pretty much the reason for increased risk.
But for Spacex the payoff was worth while as they pretty much reinvented to concept of a capsule vehicle.

Surprisingly the Rockwell X-33 did not win out as it pretty much reused the
I thought the same. Some people say that NASA deliberately went for the most ambitious of the proposals. The one with the most new technology in it. Didnt learn from the shuttle...

Typical of a NASA basher, you are talking out of both sides of your mouth.   

You said the shuttle was too great of a leap and should not have been an operational system but a technology development program.  X-33 is exactly what NASA should be doing, it was a technology development program. 

Jim, the lead up to the X-33 program was focused more on the demonstration of a viable high flight rate CONOPS than generic technology development.  While there was a desire (and need) for technology development to both support that aim and the flight rate improvement, for many of those of us involved technology (as NASA usually uses the term) wasn't the prime driver.  (In fact, I lost the argument that a high mass fraction demonstration for SSTO had to be a primary component of DC-X along with the operability demo.)

Further, Gary Payton specifically told me that as Source Selection Authority he chose the most ambitious of the proposals (this was also echoed at the public announcement, though I don't recall if Gary or Dan Golden said it).  Since I regard Gary as a friend, it pained me to have to publicly disagree with his management of the X-33 in front of a Congressional committee a short while afterwards – he and I being the only two witnesses.  I still think selecting the LM proposal was  a serious error of judgement.  And while I personally promoted the MDAC VTOL approach, I would have been much happier to see Rockwell win (with a very fine proposal, I might add) in place of LM.

(I hasten to add that "technology" is so generic a word in our business as to be almost meaningless.  I wanted to see development and test progress on a number of fronts, but felt that propulsion (a major focus of X-33's efforts) need not be among them.  The RL-10 used for DC-X and even the SSME of the day would have been perfectly acceptable to employ for a near SSTO demonstrator that could have flown on a weekly basis, for example.)

OT but the X-33 being so tightly tied to Venture star was it's biggest problem.
When the composite tanks ran into delays they should have went ahead and flew it with metal tanks.

Back on topic on the OTV-2 flight they did demonstrate the storage of a complex reentry vehicle in space for the duration of a Mars Mission.

[Star One]

A small update from the USAF about the X-37B.

The X-37B reusable spaceplane has “great utility” and the Air Force intends to keep using it “for a while” because it is helping service officials understand the “re-usability aspect of space” for satellites, said Gen. John Hyten, Air Force Space Command boss, on Thursday at AFA’s Air Warfare Symposium in Orlando, Fla. “That is the fundamental thing that X-37 is really getting at,” he said during a meeting with reporters. Pretty much everything the Air Force does in space is “a throwaway,” said Hyten.

http://www.airforcemag.com/DRArchive/Pages/2015/February%202015/February%2013%202015/The-X-37B-and-the-Satellite-Throwaway-Paradigm.aspx