After decades of dreams, a commercial spaceplane is almost ready to fly | Hacker News Reader

After decades of dreams, a commercial spaceplane is almost ready to fly

arstechnica.com

72 pointsdanboarder55 comments

Nice.

They're going directly from helicopter drop tests of landing on a runway to a launch with docking at the ISS. No suborbital flight and landing first. No orbital flight without docking first. That's ambitious. If it works, that will be impressive.

There's a "national security version" being planned. This looks much like the US Space Force's official painting.[1]

[1] https://www.spaceforce.mil/News/Article-Display/Article/3566...

This Dream Chaser thing reminds me a rarely known USSR orbital "passanger" spaceplane MiG-105[1] from 70s codenamed "Spiral", as it shares same concept. It made a couple of successful suborbital flights, but then the programme was cancelled in favour of Buran[2].

[1] https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-105 [2] https://en.wikipedia.org/wiki/Buran_(spacecraft)

It reminds me of the space craft that inspired the crash at the beginning of each episode of "The Six Million Dollar Man" - https://airandspace.si.edu/stories/editorial/crash-made-famo...

The Ars Technica piece mentions that the Dream Chaser design goes back to spy footage of the Soviet BOR-4, which is also mentioned in the first Wikipedia article.

> roughly half of the [NASA space] shuttle's habitable volume

> it features an add-on cargo module that is not reusable.

It's hard for me to get excited about this when Starship dominates it in size and (I'm guessing) cost per kg to orbit, on a similar time frame. It's only useful in a world where Starship fails its reusability goals. While Starship's success isn't certain, I wouldn't bet a company on its failure.

At least the landing mode of the Dream Chaser is different and allows landing on a runway, not to a Mechazilla installation.

It’s Super Heavy (the first stage) that requires stage 0/mechazilla. Starship (the second stage) will land on a concrete pad, similar to the Falcon 9.

Comparisons with Starship are not really warranted in this case since that's not the sort of thing this is meant to do in the first place. This is supposed to dock to the ISS, and these current versions aren't crew capable.

Starship is more than likely simply too large and heavy to dock to the aging ISS, it'd stress the structure a lot and the ISS's attitude control likely couldn't handle it, so there would be all sorts of complexity involved to allow Starship to use its own hot gas thrusters to assist in attitude control.

The value of current dreamchaser is in providing a more competitive alternative to Cargo Dragon in bringing stuff back down to the ground (compared to the embarrassment that is Starliner). In particular, Dreamchaser should offer a smoother descent with easier handling of time sensitive materials since it'd be down at a runway rather than needing to be fished out of the water and the material flown over with a helicopter.

The original space shuttle was built with the cold war in mind, a predecessor of sorts to the current hypersonic gliders and space planes. I am not sure what the dream chaser is trying to achieve. It really ought to be bigger if it wants to get a good return on investment.

If Starship can't dock to ISS then use a small capsule as a tender. The capsule wouldn't need long term life support or large engines or a heat shield, it could be relatively simple and cheap.

Or better, why even go to ISS, one Starship has more habitable volume than the whole thing...

Just because Airbus A380s exist doesn’t mean A320s don’t have a role.

If you just need to get two people to a certain place in orbit, why would you launch a starship if a dreamchaser would do?

Just need to strap it on a fully reusable booster.

I suspect in the long term Starship will be limited by the number of suitable landing locations. They’re loud when landing.

Another allegory may be trains vs cars. I suppose Starships will mainly fly to huge stations, and to build new stations, while something like Dreamliner will fly to smaller stations, to service or deorbit small satellites, to quickly ship packet back to anywhere on earth or as emergency escape vehicles for stations.

If A380s were cheaper per flight than A320s, we'd use them for almost everything. Airport too small? Make it bigger and save money. If reusability works as planned, Starship could be cheaper per launch than this thing, which is not fully reusable.

It's sobering how much less ambitious the Dream Chaser space plane is compared to the plans for the VentureStar:

https://en.wikipedia.org/wiki/VentureStar

It sometimes seems technology is going backwards.

If we're comparing against fictional vehicles, the Enterprise had interstellar warp drive in 1966.

The VentureStar was very much possible technology, the reason for cancellation was fairly minor.

The inventor of the PICA heatshield does not think it was a very possible technology [1].

As evidence, nobody since has tried to revive it.

1 - https://youtu.be/g3gzwMJWa5w?t=460

"Very much" is out of place here. X-33 had 5 risky technologies to prove, and any failure with them could ground the project. Formally they failed when the composite tank structure broke (the liquid gas evaporated and composite layers detached), but even with the proposed fix (a more conservative and less performant aluminum tank) they still had to clear the other problems.

So, Venture Star probably was just "possible technology". Still risky at the time, at the beginning of the millennium.

It clearly wasn't all that minor, the story is always told as if it'd have been fine if Congress just allowed the alternate tanks, but it's worth considering that the work with the aerospikes was still so incomplete and risky, that even now, no serious company will risk attempting them, with the leaders by far in rocket engine tech, SpaceX, opting for the ridiculous complexity of Raptor over aerospikes.

Then besides all that, VentureStar was never going to be able to overcome the issue of rocket SSTOs just not being efficient in Earth gravity. It's just way more efficient and not much more risky to have two stages.

Of course Starship is a better design now, but the VentureStar had a shot a full reusability long before it, and all that with a small fraction of the Cost-plus budget of the Space Shuttle.

The Dream Chaser certainly doesn't achieve full reusability, and it is doubtful whether it is even overall better than Dragon on Starliner.

The point is that it didn't have an efficient (and therefore cost effective) shot at full reusability. That's always been the key issue.

There were plenty of designs for partially or fully reusable spacecraft, none were done in a way to be cost effective. The space shuttle being the poster child for this sort of thing, so expensive to refurbish that being reusable was almost meaningless.

As an SSTO, VentureStar's payload would've been very limited compared to a two stage rocket of the same fuel capacity. The X-33 prototype that was being built was a scaled down suborbital version which doesn't even list a payload amount.

The VentureStar was explicitly designed for low refurbishmemt demands given the failures of the Space Shuttle. The latter was developed by NASA using contractors, which pretty much always results in extremely high costs, e.g. recently with the cancelled NASA space suits or SLS. Even with Hydrogen, I think the full reusability of the VentureStar could have outweighed its high fuel cost, compared to other rockets at the time. They estimated 20 tons to LEO, which would have been more than e.g. Atlas, which wasn't even designed to fly humans, and would have required a capsule that reduces effective payload.

*2245

Tomorrow is Yesterday

> almost

I just want an SSTO like Skylon to become reality.

I was hoping for a Skylon update as well

Unfortunately to get into orbit at least 90% of your mass has to be fuel. That means unless there's a breakthrough we will still need multistage rockets. Skylon's a good start but still needs to carry a lot of fuel.

They've nominally solved airbreathing rocket engines through to the edge of the atmosphere, have you looked into the SABRE engine?

And even with a breakthrough that new technology may just make multi stage rockets better. Instead of SSTO spacex just get to launch more payload or fuel.

slylon could facilitate airline like service to Leo. sure it is a lot of fuel, but not stacking required and smooth runway takeoff and landings. for human transport to Leo, a skylon like ship would likely be a more familiar service, and easier logistics for fast turn arounda

SSTO is unlikely to happen, because every SSTO design becomes better when you modify it to be TSTO.

See this video explanation: https://www.youtube.com/watch?v=Mk16En1qqEY

Every SSTO except Skylon. The video explanation conveniently doesn't talk about what fueling in flight does to numbers.

What problem does this solve that justifies the big booster that's still required?

It’s mentioned in the article: soft landing is much more comfortable for people, allows carrying animal and plant specimens back to earth, and can land close to actual facilities instead of kilometers out in the ocean.

The booster would be used anyway to send cargo to the ISS, you just need a bit more fuel for the added spacecraft weight.

> after decades of dreams

I wonder who are the people that dream about commercial spaceplanes and not affordable housing and healthcare...

People who already have a home and can afford their healthcare?

Affordable housing is a solved problem, but people don’t like the solution of allowing people to build housing all over the place.

Agreed in principle, but "all over the place" is worth debate. High density is the way to go versus suburban sprawl. I understand the appeal of a suburban home (been there, done that) but it comes at great cost.

Yeah you can only dream about 1 thing forever. Can’t have multiple things you dream about unfortunately :(

Hi. I dream about commercial spaceplanes. Maybe I can help you understand it a little!

What's holding us back from affordable healthcare and houses? Humans.

What's holding us back from affordable spaceplanes and cool rockets? Physics!

When I fight with humans, people get angry with me.

When I fight with physics, cool stuff happens and physics doesn't (usually) get angry with me!

So, for a conflict-averse nerd who likes to dream about cool stuff, spaceplanes > endless committee meetings.

Any more questions?

https://xkcd.com/2368/

> and not affordable housing and healthcare

Those rich enough to not need (young?) or have any healthcare they want/need and egoistic enough to not to care about housing (for others).

Is it really space when it’s only 200 miles up? You can bike that far in a day if you get up early.

No one can do 200 vertical miles in a day right? Pick your slope, still not gonna happen.

Well, it's possible if you pick -100%, at least for those pieces of yourself and the bike that survived the reentry.

Yes https://what-if.xkcd.com/58/

The part about the beats in the proclaimers song is startlingly good communication.

This is a really great link!

> Getting to space is easy. It's not, like, something you could do in your car, but it's not a huge challenge. You could get a person to space with a small sounding rocket the size of a telephone pole. The X-15 aircraft reached space just by going fast and then steering up.

> But getting to space is easy. The problem is staying there. [...] To avoid falling back into the atmosphere, you have to go sideways really, really fast.

This image accompanies the above excerpt: https://what-if.xkcd.com/imgs/a/58/orbit_x15.png

Space is generally considered to start at either 100 km or 60 miles up, so 200 miles is squarely in space. Before the Space Shuttle was retired, the ISS orbited at just over 200 miles for years.

> only 200 miles up

Statements like this always cause me to reflect on the breathtaking achievements in powered flight over the past 100 years.

I think you forgot the part where you are supposed to go 200mph up and not sideways, but okay let's play this game and assume a 100% incline.

Here you go: https://youtube.com/watch?v=n_cHSx7VM18

Unfortunately my maximum cycling speed is well short of 7-8 km/s

There's a lot less "up" and "down" in the world than there is "around" and "across".

Incredibly difficult heights to achieve are very frequently quite commonplace distances to cover. It's weird, but it's just part of living on a planet dominated by gravity.

Very much yes: https://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line

Space[0] is easy, orbit[1] is hard.

[0] The Kármán line, where aerodynamics are less important than orbital dynamics, is only 100 km up.

[1] You're always falling. The trick is to go sideways so fast you keep missing the ground.

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