After years of development and delays, SpaceX’s Crew Dragon is ready to launch into orbit. It’s the first commercially built and operated crewed spacecraft ever to do so, and represents in many ways the public-private partnership that could define the future of spaceflight.
Launch is set for just before midnight Pacific time — 2:49 Eastern time in Cape Canaveral, where the Falcon 9 carrying the Crew Dragon capsule will take off from. It’s using Launchpad 39A at Kennedy Space Center, which previously hosted Apollo missions and more recently SpaceX’s momentous Falcon Heavy launch. Feel free to relive that moment with us, while you’re here:
The capsule has been the work of many years and billions of dollars: an adaptation of the company’s Dragon capsule, but with much of its cargo space converted to a spacious crew compartment. It can seat seven if necessary but given the actual needs of the International Space Station, it is more likely to carry 2 or 3 people and a load of supplies.
Of course it had to meet extremely stringent safety requirements, with an emergency escape system, redundant thrusters and parachutes, newly designed spacesuits, more intuitive and modern control methods, and so on.
Crew Dragon interior, with “Ripley.”
It’s a huge technological jump over the Russian Soyuz capsule that has been the only method to get humans to space for the last 8 years, since the Shuttle program was grounded for good. But one thing Dragon doesn’t have is the Soyuz’s exemplary flight record. The latter may look like an aircraft cockpit shrunk down to induce claustrophobia, but it has proven itself over and over for decades. The shock produced by a recent aborted launch and the quickness with which the Soyuz resumed service are testament to the confidence it has engendered in its users.
But for a number of reasons the U.S. can’t stay beholden to Russia for access to space, and at any rate the commercial spaceflight companies were going to send people up there anyway. So NASA dedicated a major portion of its budget to funding a new crew capsule, pitting SpaceX and Boeing against one another.
SpaceX has had the best of Boeing for the most part, progressing through numerous tests and milestones, not exactly quickly but with fewer delays than its competitor. Test flights originally scheduled for 2016 are only just now beginning to take place. Boeing’s Starliner doesn’t have a launch date yet but it’s expected to be this summer.
Tonight’s test (“Demo-1”) is the first time the Crew Dragon will fly to space; suborbital flights and landing tests have already taken place, but this is a dry run of the real thing. Well, not completely dry: the capsule is carrying 400 pounds of supplies to the station and will return with some science experiments on board.
After launch, it should take about 11 minutes for the capsule to detach from the first and second stages of the Falcon 9 rocket. It docks about 27 hours later, early Sunday morning, and the crew will be able to get at the goodies just in time for brunch, if for some reason they’re operating on East Coast time.
SpaceX will be live streaming the launch as usual starting shortly before takeoff; you can watch it right here:
SpaceX’s futuristic Starship interplanetary craft may embody the golden age of sci-fi in more ways than one: in addition to (theoretically) taking passengers from planet to planet, it may sport a shiny stainless steel skin that makes it look like the pulp covers of old.
Founder and CEO Elon Musk teased the possibility in a picture posted to Twitter, captioned simply “Stainless Steel Starship.” To be clear, this isn’t a full-on spacecraft, just part of a test vehicle that the company plans to use during the short “hopper” flights in 2019 to evaluate various systems.
As with most Musk tweets, this kicked off a storm of speculation and argument in the Twitterverse.
The choice surprised many because for years, modern spaceflight has been dependent on advanced composite materials like carbon fiber, which combine desirable physical properties with low weight. When metal has been required, aluminum or titanium are much more common. While some launch components, like the upper stage of the Atlas 5 rocket, have liberally used steel, it’s definitely not an obvious choice for a craft like the Starship, which will have to deal with both deep space and repeated reentry.
As Musk pointed out in subsequent comments, however, stainless steel has some advantages versus other materials when at extremely hot or cold temperatures.
Usable strength/weight of full hard stainless at cryo is slightly better than carbon fiber, room temp is worse, high temp is vastly better
This is a special full-hardness steel alloy mentioned as being among the 300 series of high-strength, heat-resistant alloys — not the plentiful, pliable stuff we all have in our kitchens and buildings. Musk also mentioned another “superalloy” called SX500 that SpaceX’s metallurgists have developed for use in the Raptor engines that will power the vehicle.
Many craft and reusable stages that have to face the heat of entering the atmosphere at high speed use “ablative” heat shielding that disintegrates or breaks away in a controlled fashion, carrying heat away from the vehicle.
It’s unlikely this is a possibility for Starship, however, as replacing and repairing this material would necessitate downtime and crews wherever and whenever it lands, and the craft is meant to be (eventually) a quick-turnaround ship with maximum reusability. Heat shielding that reflects and survives is a better bet for that — but an enormous engineering problem.
Scott Manley put together a nice video illustrating some of these ideas and speculations in detail:
Musk said before of the Starship (then still called BFR) that “almost the entire time it is reentering, it’s just trying to brake, while distributing that force over the most area possible.” Reentry will probably look more like a Space Shuttle-esque glide than a Falcon 9 first stage’s ballistic descent and engine braking.
The switch to stainless steel has the pleasant side effect of making the craft look really cool — more in line with sci-fi books and comics than their readers perhaps ever thought to hope. Paint jobs would burn right off, Musk said:
Skin will get too hot for paint. Stainless mirror finish. Maximum relfectivity.
You can’t expect it to stay shiny for long, though; it may be stainless, but like a pan you left on the stove, stainless steel can still scorch and the bottom of the Starship will likely look pretty rough after a while. It’s all right — spacecraft developing a patina is a charming evolution.
Details are still few, and for all we know SpaceX could redesign the craft again based on how tests go. Next year will see the earliest hopper flights for Starship hardware and possibly the Super Heavy lower stage that will lift its great shiny bulk out of the lower atmosphere.
The technical documentation promised by Musk should arrive in March or April, but whether it will pertain solely to the test vehicle or give a glimpse at the craft SpaceX intends to send around the moon is anyone’s guess. At any rate you should expect more information to be spontaneously revealed before then at Musk’s discretion — or lack thereof.