Sierra Space Dream Chaser DISCUSSION Thread (was SNC)

[Lee Jay]

We have arrived at a profound milestone in both our company’s journey and our industry’s future,” said CEO Tom Vice.

Tenacity, the first vehicle in the Dream Chaser fleet is complete, and will ship to NASA’s Neil Armstrong Test Facility in coming weeks.

I'm glad they're getting closer to shipping, but judging by the photos their definition of complete must be pretty loose.

Sometimes things need to be partially disassembled for shipping, to get to tie-down points and such.  Maybe the missing bits are for that or a related purpose.

[Robert_the_Doll]

Some of those "bare" areas on Tenacity appear to just need closeout panels installed, and in others, it will just require some some the thermal tile-covered panels to be placed over the aluminum alloy skin of the airframe.

[edzieba]

I don't believe that this image of crewed DC has been posted in this thread before:

https://twitter.com/DutchSpace/status/1722609536492786015

The image below has been posted in this thread before but was enhanced to show more details:

https://twitter.com/DutchSpace/status/1613486689686528001

DC-201 has no 'shooting star' separable payload module, and has a larger internal volume for the same length (more cylindrical, rather than Dream Chaser's flattened form). Eliminating the forward-facing-window requirement and its associated dorsal hump certainly simplifies things.

[JAFO]

Suppose an astronaut had a medical emergency that made it hazardous to return on a higher G capsule like Dragon or Soyuz. Even though it will not be going through the human rating tests, is it possible DC Cargo could be used to return them?
Yeah, they'd have to figure out a way to strap them in, but suppose it was a stroke or cardiac event or whatnot, and NASA was faced with a no-win situation. I wonder if there is sufficient ECS to get the person down to the surface?

[Zed_Noir]

Suppose an astronaut had a medical emergency that made it hazardous to return on a higher G capsule like Dragon or Soyuz. Even though it will not be going through the human rating tests, is it possible DC Cargo could be used to return them?
Yeah, they'd have to figure out a way to strap them in, but suppose it was a stroke or cardiac event or whatnot, and NASA was faced with a no-win situation. I wonder if there is sufficient ECS to get the person down to the surface?

Just strapped the patient to an improvised seat in the patient's IVA suit with portable air supply for at least 6 hours. However it is likely that someone have to accompany the patient down. Also the Cargo Dreamchaser will probably landed at a contingency landing site that is the closest available after the medical emergency is declared. Presuming there will be several portable air supply system stored aboard the ISS for medical evacuation with the Cargo Dreamchaser.

[FutureSpaceTourist]

https://twitter.com/brickmack/status/1730974158895321416

Dream Chaser jettisons its Shooting Star prior to reentry

[edzieba]

DC201 briefly depicted (2:51) docking in Sierra Space's update video on LIFE testing. IDS rather than CBM, and no service module (Shooting Star).

[JAFO]

No presser about the results of testing, must mean the tests are going well?

NASA, Sierra Space Invite Media to See Spaceplane for Cargo Missions
As part of NASA’s efforts to expand commercial resupply in low Earth orbit, media are invited to view Sierra Space’s uncrewed commercial spaceplane ahead of its first demonstration flight for the agency to the International Space Station in 2024.
The Dream Chaser event is scheduled to begin at 10:15 a.m. EST Thursday, Feb. 1, at NASA’s Neil Armstrong Test Facility in Sandusky, Ohio.
For the first time, the spaceplane is coupled with its companion Shooting Star cargo module in a 55-foot-tall vertical stack for environmental testing in the Mechanical Vibration Facility at Armstrong Test Facility’s Space Environments Complex.
During the event, the following officials will provide brief remarks about the agency’s efforts to enable commercial industry, the unique capabilities of the NASA test facility, as well as share more about Dream Chaser and its ongoing testing at NASA Glenn:
 

Dr. Jimmy Kenyon, director, NASA’s Glenn Research Center in Cleveland

Tom Vice, chief executive officer, Sierra Space

A question-and-answer session will follow remarks. Dr. Tom Marshburn, former NASA astronaut and chief medical officer for Sierra Space, also will be in attendance and available for interviews.
Media interested in attending must RSVP by 2 p.m. Wednesday, Jan. 31, to Brian Newbacher at [email protected] or 216-433-5644.
Attendance is in-person only and limited to participants, invited guests, and credentialed media.
Dream Chaser and its cargo module are undergoing testing on NASA’s spacecraft shaker table, exposing the stack to vibrations like those it will experience during launch and re-entry to the Earth’s atmosphere. Armstrong Test Facility is part of NASA Glenn. Located on 6,400 acres, it is home to some of the world’s largest and most capable space simulation test facilities, where ground tests are conducted for the U.S. and international space and aeronautics communities.
In 2016, NASA awarded a Commercial Resupply Services-2 contract to Sierra Space to resupply the International Space Station with its Dream Chaser spaceplane and companion Shooting Star cargo module. NASA is opening access to space to more science by enabling commercial resupply missions to the International Space Station for the crew members aboard the microgravity laboratory. The agency is helping build a low Earth orbit economy where NASA is one of many customers of U.S. private industry for cargo, crew, and space destinations for the benefit of humanity. As NASA transitions low Earth orbit to industry, the agency also is returning to the Moon as part of Artemis in preparation for Mars.
Learn more about Dream Chaser at:
https://go.nasa.gov/3Oe9wi0

https://www.nasa.gov/news-release/nasa-sierra-space-invite-media-to-see-spaceplane-for-cargo-missions/
[/l][/l]

[/list]

[JAFO]

Watching Tenacity's flight continue to slip to the right, just curious what people's thoughts are.
Is it because "Space is hard?", or because they're taking their time, or they're encountering problems but not disclosing them (which is none of my business anyway), or.....?



Don't get me wrong, I'm not throwing rocks. Space IS hard, and I'd rather see SNC take their time and get it right.

[deltaV]

Watching Tenacity's flight continue to slip to the right, just curious what people's thoughts are.
Is it because "Space is hard?"

Most spacecraft designers choose recovery methods other than landing on runways, presumably because runway recovery adds complexity for little gain. Maybe the common wisdom was correct this time.

[spacebleachers]

Watching Tenacity's flight continue to slip to the right, just curious what people's thoughts are.
Is it because "Space is hard?", or because they're taking their time, or they're encountering problems but not disclosing them (which is none of my business anyway), or.....?

After reading Eric Burger’s article, it appears they are having trouble managing schedules and timelines.

[JEF_300]

Watching Tenacity's flight continue to slip to the right, just curious what people's thoughts are.
Is it because "Space is hard?"

Most spacecraft designers choose recovery methods other than landing on runways, presumably because runway recovery adds complexity for little gain. Maybe the common wisdom was correct this time.

I mean, as ever, it heavily depends on what you're trying to accomplish. If you just want to get the vehicle back down safely and/or cheaply, which is the ultimate goal for most spacecraft landings, then wings clearly aren't it. But if you have more discerning requirements for whatever reason, especially if those requirements includes either the phrase "cross-range" or the phrase "maximum G-forces", then wings and lifting bodies and runways are your friends.

[adrianwyard]

Sierra Space (and their previous incarnations) have always held their cards very close to the chest, so we remain in the dark as to whether delays are due to honest schedule optimism running into 'space is hard' reality, strategic scheduling shortening despite their knowledge of the actual time needed, or major unforeseen problems that are hit and quietly resolved causing slips. Given how long this project has been under way it's probably some of each.

I'd bet the delays in recent years are mainly due to the fact that they've just never made a ~human rated spacecraft of *any* kind before, and had to learn a lot their first time out. i.e. a conical capsule wouldn't have been much quicker. They are going from zero (spacecraft components) to a re-usable autonomous lifting body spacecraft that is the first to use all carbon-fibre main structure. That's plenty.

[deltaV]

But if you have more discerning requirements for whatever reason, especially if those requirements includes either the phrase "cross-range" or the phrase "maximum G-forces", then wings and lifting bodies and runways are your friends.

What customer is willing to pay billions of dollars for those requirements?

[Tomness]

But if you have more discerning requirements for whatever reason, especially if those requirements includes either the phrase "cross-range" or the phrase "maximum G-forces", then wings and lifting bodies and runways are your friends.

What customer is willing to pay billions of dollars for those requirements?

NASA & DOD will. Specially bringing billion dollar Sats back

[adrianwyard]

As I understood it the main selling point of lifting bodies and Dream Chaser in particular is that they theoretically give you low-g entry and runway landings while still being essentially blunt body vehicles. i.e. these capabilities shouldn't cost billions more than a capsule. In contrast to winged vehicles like STS or X-20 the mass of the fins (not wings) is relatively low and the vehicle is more volume efficient. The reality may not match the aspiration, but I believe that was the idea.

[Jim]

But if you have more discerning requirements for whatever reason, especially if those requirements includes either the phrase "cross-range" or the phrase "maximum G-forces", then wings and lifting bodies and runways are your friends.

What customer is willing to pay billions of dollars for those requirements?

NASA & DOD will. Specially bringing billion dollar Sats back

that would wrong

[JEF_300]

But if you have more discerning requirements for whatever reason, especially if those requirements includes either the phrase "cross-range" or the phrase "maximum G-forces", then wings and lifting bodies and runways are your friends.

What customer is willing to pay billions of dollars for those requirements?

NASA is literally paying for it now, and has been for a decade, and doing so on top of paying for two other cargo vehicles.

[deltaV]

NASA is literally paying for it now, and has been for a decade, and doing so on top of paying for two other cargo vehicles.

NASA is paying for Dreamchaser in CRS2 but I skimmed the CRS2 source selection statement (https://www.defensedaily.com/wp-content/uploads/post_attachment/132009.pdf or https://web.archive.org/web/20160322014034/http://procurement.jsc.nasa.gov/sss/CRS2%20Source%20Selection%20Statement.pdf) and lifting body advantages don't seem to have been a significant factor in the selection. I didn't see anything in there about low gee or cross range. It did mention accelerated return as an advantage of DreamChaser, which is probably possible because they're landing on a runway rather than the middle of the ocean. But that was only one minor thing out of many pages of other differences between the bidders. So CRS2 doesn't justify spending extra money on a lifting body.

The nice thing about competitive fixed price contracts like CRS2 is the fact that if it was a mistake to make a lifting body that mistake is primarily Sierra's problem, not NASA's.

[sdsds]

Runway landings theoretically imply quick vehicle turn-around for reflight, assuming launcher availability. With "first flight in the fourth quarter of this year" the question becomes how soon the same vehicle can launch again.