Dr. Robert Zubrin, President of the Mars Society, recruits new members as they wait to hear from SpaceX chief Elon Musk. Credit: Joe Mascaro
In an interview at the International Astronautical Congress in Guadalajara, Mexico, Dr. Robert Zubrin, engineer and author of The Case for Mars, expressed serious reservations about certain components of Elon Musk’s recently announced Mars architecture, while heaping praise on SpaceX and Musk himself.
“He is the opposite of Donald Trump. While they’re both rich, they both have egos, Elon wants to repair the world. That is his imperative. He looks around the world and says: “what could I do that would have the greatest possible impact for the human future?’”
Still, Zubrin had several concerns with the recently unveiled Mars architecture.
“I was hoping he would’ve spent more time talking about what he’s actually going to do over the next 10 to 15 years with respect to sending Dragons to Mars, and what has sometimes been mentioned as human landings on Mars in the mid to late 2020s. It would’ve been extremely exciting.”
Musk indeed spent little of the announcement on near-term missions with existing hardware, such as Falcon Heavy, which is due to conduct its first flight in 2017. And, at least in Muskian terms, he was surprisingly vague about the target date of the first flight of the Interplanetary Transport System.
Of the four keys that Musk laid out in his vision: full reusability of flight hardware, on-orbit refilling, propellant production on Mars (using in situ resource utilization) and choosing the right propellant (a methane-oxygen mixture), Zubrin embraced most of them. Some, particularly the propellant themes, follow from the approach Zubrin co-designed for the Mars Direct mission plan laid out in The Case for Mars. Zubrin also added a strenuous recommendation that SpaceX deploy test articles to conduct in situ methane and oxygen production from the martian atmosphere and regolith on early Red Dragon missions.
“I think there were a lot of interesting and valuable ideas in his presentation. But the design as laid out was not practical. He has this whole giant spaceship going all the way from LEO to the surface of Mars, refilling it all, and shooting it all back. That’s certainly a very simple architecture, but it’s suboptimal because this ship is going to get back too late for the next launch window, so it can only be used every other launch window.”
The Mars Desert Research Station in Utah, owned and operated by the Mars Society.
If instead, Zubrin argued, the spaceship was used as a stage to accelerate a smaller payload, the craft could remain in a high-Earth orbit, aerobrake to circularize, refuel, and repeat the acceleration of another Mars-bound payload in just a few weeks.
As Zubrin described in a statement from the Mars Society: “Used this way, the big Earth escape propulsion system could be used five times every launch window, instead of once every other launch window, effectively increasing its delivery capacity by a factor of ten. Alternatively, it could deliver the same payload with a system one-tenth the size, which is what I would do.”
This smaller-mass, but perhaps, more agile system, Zubrin noted, would be available much sooner, and could be powered by Falcon Heavy, which already exists.
Despite the determination of his rebuttal, Zubrin felt that Musk and SpaceX had unquestionably raised the bar when it comes to innovating the hardware needed to get humans to Mars. “And so, New Glenn [Blue Origin’s recently unveiled rocket] better have a reusable first stage, and suddenly… SLS [NASA’s Space Launch System] is looking like a thing of the past with its expendable first stage.”
When it comes to humans-to-Mars discussions, NASA culture continues to stupefy Zubrin, who has been sharply critical of the agency in the past. “If they don’t have problems they can use as excuses, they make them up.”
These invented problems, in Zubrin’s view, begin with radiation risk. “The guys that just spent a year on the ISS got the same radiation dose as they would on a six-month transfer to Mars.”
Zubrin took an interest in Musk before the entrepreneur started SpaceX, amazed that—unlike other tech billionaires who dabbled in space exploration by “writing checks to engineers,” Musk became deeply invested. “When I first met Elon, he knew nothing about rockets. But he had a scientific mind. And by 2007 he knew everything… He put himself into it. And he had the technical talent, the business talent, and the political talent to make this go as far as its gone.”
“He’s really moved the needle. First of all, he’s developing things in 1/3rd the time at 1/10th the cost. So he’s changing the standard. Number two, he’s now developing things that have never been developed: reusable first stage, supersonic retropropulsion—which, by the way, blows up this notion that we can’t land heavy payloads on Mars.”
On whether Musk would ultimately succeed, Zubrin left no doubt: “Elon Musk is not looking to use problems as excuses. He’s looking to knock problems out of the way. And it’s that attitude that’s going to take him to Mars.”
Conscious of Zubrin’s affection for explorers Magellan and Cook, I asked Zubrin if he thought Musk was an explorer.
He paused for nearly a minute, before saying simply:
“Elon is a hero.”
Joe Mascaro is Program Manager for Impact Initiatives at Planet, a satellite Earth imaging corporation headquartered in San Francisco, CA. The views expressed in this article are the author’s own, and do not reflect the views of Planet. Quotations were lightly edited for clarity.