NASA & World Space Exploration...News, Views, Photos & videos


gelgoog

Brigadier
Registered Member
Which is unlikely. The SLS system is unbelievably expensive due to the fact it was built to a specific mission, based on a mandated specification with mandated parts in a non bid process to a mission that at this point NASA doesn’t actually have the hardware for.
...
The fact is though Soviet papers pushed it from the front page, They begrudgingly acknowledged it. It’s only in modern Russia where they question it.
Actually the Apollo landing was news on the front page of Pravda on 22nd July 1969. I would not say the Soviets "begrudgingly" acknowledged it. Back then a lot of people saw all space successes as a triumph of humanity. A bit like the Olympics it wasn't nice not seeing your team win, but you enjoyed the show anyway.

The SLS is not called the "Senate Launch System" for anything. It is pure pork barrel politics. A lot of congresscritters including the gentleman from Alabama wanted something to "keep NASA jobs" or whatever. And that was it. Much like JWST ate away the rest of NASA's science budget, the SLS is eating the exploration budget. JWST has now been launched, but SLS, I think it just needs to be canned. Especially once Vulcan, New Glenn, and Falcon Heavy are all available. It needs to be reconsidered and re-bid. They need to focus funding on the lunar or martian payloads and the program should not be tied to any one vehicle.
 

taxiya

Brigadier
Registered Member
SLS is a pointless vehicle. The US has the Falcon Heavy. Which is a vehicle actually in service which is way more cost effective.
You do realize that Falcon Heavy is a 2 stage rocket that has much worse performance to orbit beyond earth? It's GTO is 26.7t, to Mars at 16.8t according to wiki, a guess of TLI would be around 20t.

Artimis I's TLI is 33.4t
(Orion + ESM), how is Falcon Heavy able to do this job?
 

AndrewS

Brigadier
Registered Member
You do realize that Falcon Heavy is a 2 stage rocket that has much worse performance to orbit beyond earth? It's GTO is 26.7t, to Mars at 16.8t according to wiki, a guess of TLI would be around 20t.

Artimis I's TLI is 33.4t
(Orion + ESM), how is Falcon Heavy able to do this job?

It would be cheaper to use 2 Falcon Heavy
 

gelgoog

Brigadier
Registered Member
Falcon Heavy has a low thrust and low Isp second stage. They are basically using the same second stage as on a regular Falcon 9.
The USAF funded development of a Raptor engine for the Falcon Heavy second stage several years ago.
The other rockets can use RL-10 powered second stages or better.

Like @AndrewS said Falcon Heavy is so cheap even without those changes it has lower cost per ton. Just consider it can even reuse the boosters, while this SLS is a disintegrating totem pole. There is simply no good economical or otherwise reason not to consider multiple Falcon Heavy launches per mission. The original lunar mission designs by the US and the Soviets used multiple launches. They gave up on it because of issues with getting automatic docking to work properly back then. But this is the XXIst century. That problem has long since been solved.
 
Last edited:

taxiya

Brigadier
Registered Member
It would be cheaper to use 2 Falcon Heavy
But you can't split the Orion + ESM stack in two, can you? Or you have to re-design everything from ground up.

@gelgoog
Like @AndrewS said Falcon Heavy is so cheap even without those changes it has lower cost per ton. Just consider it can even reuse the boosters, while this SLS is a disintegrating totem pole. There is simply no good economical or otherwise reason not to consider multiple Falcon Heavy launches per mission. The original lunar mission designs by the US and the Soviets used multiple launches. They gave up on it because of issues with getting automatic docking to work properly back then. But this is the XXIst century. That problem has long since been solved.
Yes SLS is a disaster but not because of its higher payload (finally 130t), otherwise how do you explain the existence of Starship? Falcon Heavy isn't up to the moon task no matter how cheap it could be. The problem with all the argument of multiple launches is that many missions can not be split in pieces. I think we had many times of debate on this subject, the moon shot being the one.
 
Last edited:

siegecrossbow

Lieutenant General
Staff member
Super Moderator
They can use Falcon Heavy to launch a modified version of Dragon that could rendezvous with the Starship lander in Lunar orbit.
 

gelgoog

Brigadier
Registered Member
Dragon does not have enough supplies for long endurance lunar mission supposedly. So you would need some sort of expendable orbital module for it similar to the one on Soyuz. Dragon supposedly should already have a heat shield capable of lunar return reentry speed though.

Orion is way heavier because of the long endurance mission requirement. It can store way more consumables.

NASA used to have a plan to use space tugs or some sort of lunar cycler type ship at one point. You would dock the manned capsule to it and that would do most of the legwork of the trip. But you would need to refill it with consumables like oxygen, water, and fuel somehow. Not impossible since that is what Progress capsules do to ISS. And I think Cygnus capsule can also do this.

The whole SLS thing just suffers too much from Apollo redux syndrome. A modern lunar architecture does not need to look like that and in fact that architecture is inefficient in terms of mass and cost to begin with.
 
Last edited:

Top