Could SpaceX's Dragon V2 or the Boeing Starliner be upgraded to travel beyond LEO

Question

A recent Government Accountability Office (GAO) report has cast doubts on the ability of the Orion MPCV to meet its requirements on its already excessive budget. Orion has been in development since 2006 and will likely continue until 2023 with costs in excess of \$20 B before crew fly on it.

As I understand the commercial crew contracts SpaceX is to receive up to \$2.6 B and Boeing is to receive up to \$4.2 B for design development and testing of the Dragon 2 and Starliner. So what I am wondering is what modifications would be needed to be made to these spacecraft to let them fly beyond LEO say to cis-lunar space. Necessary modifications I can think of include: life support systems to allow longer missions, radiation protection for crew and radiation hardened electronics, larger heat shield to allow for much faster reentry, and more robust structures for greater g-loads upon entry. Would it be possible to modify the current designs to include these requirements or would these changes require the the development of an entirely new spacecraft which would be about as expensive as the Orion?

Answer 1

It is the volume problem that must be solved to leave LEO. LEO means you can be resupplied and abort back to Earth in an emergency. With Cis lunar or farther you have a series of non-linear scaling problems that go in a step-wise fashion that greatly increase mass and volume required to "bring everything with you". Neither of these can be expanded in a way that is meaningful, regardless of the good points on limitations the comments point out like radiation shielding. In order to solve the volume and mass problem, given the rocket equation and the limitations it places on launches and mass to orbit on each launch, there is basically no way to build a deep space capable craft without making it in section and assembling it in LEO just like the ISS. Once the parts are all together and proven to function, more supplies and fuel need to be sent up, along with an second propulsion module because one failure that leads to total loss of propulsion that far away leads to total loss of crew, which is unacceptable. Same goes for other critical functions, so you must bring spare parts and the tools and expertise to replace them. On the ISS they remove and replace, sending back to Earth for repair, not an option for far beyond LEO. Estimates for a 900 day journey (to allow the planets to align and use reasonable fuel) requires about eight fully loaded Cygnus extended capacity missions, which carry 3500 KG and are 25 m^3 each all connected together. This means that even if the Boeing or SpaceX capsules could be connected together in this way, they would need about the same of them 8-10 all connected together. This does NOT allow for MARS habitats on the ground or ascent/descent vehicles. Lets say we almost DOUBLE the mass and volume needed for that. That makes 8-9 missions sent three years in advance to pre-position in Mars orbit THEN 10 launches assembled in LEO to go with a crew of 6. So, NO, they cannot be expanded in a meaningful way to allow the occupants to live beyond LEO without another 10 missions all connected together to support.

Answer 2

The ISS crew cargo craft do not have real facilities for long term stays. There is no washroom for example.

Of course any serious beyond-LEO mission in a capsule will likely include a hab module of some kind which is not something CST-100 or Dragon is excluded from.

Gwynne Shotwell in discussing Red Dragon mentioned that deep space communication systems was one of their big issues.

SpaceX claims their heat shield is over designed for LEO reentry with sufficient margin for higher energy return missions. How high, I am sure they will experiment to find out on some mission.