Mind the gap

“We have one data point. All we need is one more and we can draw a line.” This was one of our many meetings where we dwelled on lessons learned, the Space Shuttle, and what’s next in reusable launch. As far as jokes go, at least for number crunchers, this was a good one. Except that as much as NASA invested in technology and concepts to follow the Shuttle, and we worked toward that second data point, no one could have guessed how it turned out.

From a viewing spot close to events, till about 2001, no one would have predicted the next flag-ship NASA rocket would toss aside the reusable Space Shuttle orbiters, keep the expendable solid rocket boosters and orange tank, and top it off with an old-style space capsule for crew. Although NASA always held around the idea of an extra-large launcher based on the Shuttle’s expendable parts, especially for Mars missions, these usually lost out when analysts (like myself) provided advice on what was best for the future. In retrospect, justifications for investments singled out what was not ready, technically or economically, while promising to be much more so in the future. Inversely, not making the cut led to taking it for granted, erroneously, that a Shuttle-derived expendable presented no technical difficulties, losing out merely for predictably high operating cost. The devil we know was easy to discard. Though any sense of surprise was tempered by knowing that come decision day, the allure of the known would be back at the table and own the table too.

The real surprise no one foresaw is how even as the tide clearly shifted by 2004 and NASA was going back to expendable launch, by 2015, it ended up with an advanced, break-through reusable launcher – anyway. This improbable scenario came about courtesy of NASA’s partner SpaceX evolving an initially expendable first stage (and NASA investment) into a vertically landing reusable booster. Just last week, SpaceX successfully landed and returned a booster for the 129^th time (out of 140) after placing a Dragon capsule in orbit to robotically deliver supplies to the International Space Station. If an automated drone delivers stuff to your home one day, remember NASA did it first.

As NASA makes plans for what comes after the International Space Station, the question comes up again – will the continued US human presence in space since late 2000 see a “gap” one day as happened with our ability to get there?

On top of these improbable shifts, nearly no one saw what was coming after the Shuttle’s retirement – a ten-year gap in US human spaceflight. Though as a post-Shuttle gap became inevitable, it was pointed out that before the Shuttle’s end, we had the end of the Apollo program and its gap. No US crew went to space between the Apollo Soyuz Test Project flight in 1975 and the liftoff of Columbia on its maiden flight in 1981, six years later. Eventually, the gap in US human spaceflight got its second data point, going UP from six years after Apollo to ten years after the Shuttle, even as it might have seemed that surely a six-year gap after Apollo was a fluke. We can’t use that one post-Apollo gap data point to tell us anything about a possible post-Shuttle gap. Right?

So, NASA went expendable after the Space Shuttle, after so much time and effort invested in reusable launch and technology, but NASA  got a semi-reusable launch system anyway through its partner, SpaceX, and we had no US crew launch capability for ten years. This was not quite predictable, and we had no lack of predicting.

As NASA makes plans for what comes after the International Space Station, the question comes up again – will the continued US human presence in space since late 2000 see a “gap” one day as happened with our ability to get there? Again, there is not a lot of data, which could be a blessing in disguise. We can put that next data point where we want, it would seem, as it’s not that we have lots of data spelling out the inevitable. Or do we discard the meager data points at our own risk?

Since NASA doesn’t end major space programs often, we could simply take away to expect the unexpected. Nonetheless, seeing why previous gaps occurred might tell us something useful about what else to expect. If we feel Deja-vu it might be for a reason.

NASA’s plan is for commercial space stations with global customers and markets after the International Space Station comes to an end about a decade from now. NASA “intends to implement an orderly transition from current International Space Station (ISS) operations to these new CLDs (commercial low Earth orbit destinations.)” NASA ramped up funding for its partners here in 2021, and previous experience shows it’s a wonder what NASA and its partners might accomplish with as little as $100 million a year when going commercial.

Yet relatively small amounts of yearly funding, as far as major NASA projects go, should also set off a yellow alert. The gap in US human spaceflight after the Shuttle might be blamed on a lack of funding to carry out or to accelerate a plan, but that is simply restating the problem another way instead of questioning further. Why is there a lack of funding? Better yet, it’s worth asking if this is how everyone would see it – especially the people providing (or not) the funding.

Where then did NASA get money to do what would come after the Shuttle?

If you stare at the NASA budget over time long enough, a first oddity is the lack of much *new * funding after the decision to retire the Space Shuttle. It’s easy to say NASA received plenty of funding before that to get ready for this day. Aren’t we done yet? Instead, it’s the Shuttle budget that goes up after the loss of Columbia, naturally, to improve systems before resuming its last launches to finish the construction of the ISS.

Where then did NASA get money to do what would come after the Shuttle? Much of the money for what was to come next came from existing funds. In particular, knowing your current system is being retired, NASA in 2005 (relatively) quickly diverted its existing R&D capability away from Shuttle upgrades and other research towards the specifics of developing the next thing – a large expendable launcher and spacecraft. (It’s worth remembering that before the loss of Columbia, but lacking the authorization to replace the Shuttle, NASA had a plan called “Shuttle 2020” – to keep operating the Shuttles clear through 2020.) But the efforts for what comes after the Shuttle really pick up steam only after the Shuttle ends – the next system being Shuttle derived after all, and using a now truly freed up Shuttle organization. Another good part of the freed-up funding post-Shuttle goes toward re-establishing operational capabilities to get to the ISS, today’s commercial cargo and crew services.

What might these lonely data points in the history of major NASA programs ending mean for avoiding a gap in our human presence in space post-ISS? We are perhaps a decade away from that day, but a world post-Shuttle also seemed so far away for the longest time until it was right on us. Mostly, it seems any major NASA spaceflight program has limited runway for what comes next. Next steps require a combination of investing very little funding to set the stage and waiting for much more funding once the prior program ends.

There are some wildcards – we see the new line items appearing for the Gateway, a lunar lander, and for what comes after the ISS. It would seem the post-Shuttle world continues to lead to a more diverse NASA portfolio with smaller spaceflight programs that depend on each other to complete a capability (LEO or lunar). Still, our sparse experience here says we shouldn’t expect to avoid a gap merely by saying we are mindful of the gap. Events after the loss of Columbia and the decision to end the Shuttle program led to the unexpected. For a post-ISS world, we have another opportunity to create the unexpected. This includes unexpectedly avoiding a gap as one program ends, and another builds and improves on what came before.