Wednesday, September 25, 2013

Delayed Description of Dragon Duplicated Delivery to Distant Digs (CRS-2)

This is incredibly late in coming, but here is a short note about SpaceX's second cargo delivery to the ISS via a Dragon spacecraft. This actually took place in March of this year (The craft launched on March 1st, 2013 and splashed down on March 26th, 25 days later). This mission featured thruster problems that delayed the Dragon's arrival to the ISS by 2 days. The thruster issue came down to a blockage in the helium pressurant line running to the Nitrogen Tetroxide tank. Cycling a valve cleared the blockage and the mission continued without incident. The Dragon delivered 2400 pounds of supplies to the station and returned to earth with 3000 pounds of cargo. Dragon is unique in the cargo delivery market in that it can both supply and return cargo to/from the ISS. The completion of CRS-2 marked the third successful Dragon delivery to the ISS, and the fourth successful flight of the Dragon spacecraft.

The next supply mission for Dragon is slated for November 11th, 2013.

Thursday, September 19, 2013

NASA's Case of the Missing Methane -or- Barsoomian Bugs Blatently Belchless

According to a recent JPL press release, the Mars Curiosity rover has been unable to detect traces of methane in the Mars atmosphere. This is somewhat troubling as methane has been detected from orbit by various spacecraft, but it appears as though methane is a rare or non-existent phenomena in the area surrounding the rover. This news does not bode well for Mars biology enthusiasts, as the presence of methane would be a key indicator of the presence of Martian microbial life. Since there has been little or no methane detected, one might conclude that no life exists on the red planet. Still other explanations for the lack of methane might exist: Perhaps any methane exists only in the high reaches of the Martian atmosphere. Perhaps the Martian environment is remarkably hostile towards Methane -- the soil is rich in perchlorates and the surface is bombarded with UV rays -- maybe the methane is oxidized through as yet unknown phenomena, perhaps the methane measurement instrument on the rover has somehow malfunctioned.

Since the Mars Reconnaissance Orbiter was one of the craft that identified methane previously, perhaps it would be possible to use it's measurement capability to verify that no methane is present near the rover. By cross-checking the two vehicle's data, it might be possible to figure out why the discrepancy exists. The image above is a view inside Curiosity's Tunable Laser Spectrometer. This instrument is part of the Sample Analysis at Mars (SAM) unit.

Wednesday, September 18, 2013

Congratulations to New Commercial Cargo Carrier Contender Climbing into the Cosmos

Congratulations go out this morning to Orbital Sciences and their launch of the Antares rocket carrying the Cygnus pressurized cargo carrier on their first trip up to the International Space Station. The rocket blasted off at 10:58 AM Eastern Daylight Time from NASA's Wallops Flight Facility. The Cygnus spacecraft will rendezvous with ISS on Sunday, September 22nd and deliver its 589kg (1300 pounds) of cargo. Like Spacex's first mission, this mission is considered a demonstration resupply mission, which I assume means the craft isn't carrying the crown jewels (or something equally precious and irreplaceable) up to the station. Orbital Sciences now joins SpaceX as the second commercial cargo transporter up to ISS for NASA. Both companies have contracts to supply the ISS with a multitude of cargo missions (12 for Spacex and 8 for Orbital Sciences) over the next few years. The Cygnus mission is very similar to the Progress and the JAXA HTV (transfer vehicle) in that it is designed to rendezvous with ISS to deliver it's cargo, and then be sent back down to a fiery re-entry into the South Pacific with a load of ISS trash. This makes for a relatively inexpensive spacecraft, since it isn't meant to survive re-entry. In business it's always a good idea to have multiple suppliers for your critical parts or services. So this is a positive step towards NASA being able to depend on commercial space transport services for their ISS needs.

Here is a link to a snazzy graphic from which explains the Antares/Cygnus delivery system.

Thursday, September 12, 2013

Voyager One has Left the Building...

The folks monitoring the Voyager 1 spacecraft have determined that it has left the solar system. Meaning that the spacecraft has left the part of the solar system influenced by the outward press of the solar wind. Voyager 1 is currently about 125.5 AU from the Earth and a similar distance away from the Sun. This equates to 18.7 billion kilometers away, give or take. You can see where the Voyager 1 and Voyager 2 spacecraft are right at the moment by going here. Both Voyager spacecraft were launched in 1977 destined to make "Grand Voyage"s through the solar system. They collected data and close-up pictures of the outer planets (Jupiter, Saturn, Uranus & Neptune) and used momentum transfer during their passes of the large planets to reach the highest velocities of any man-made craft for their time (17 km/sec or 61000 km/hour). NOTE: The Helios Spacecraft have reached higher velocities since, but did so by diving towards the sun along highly elliptical orbits and remaining bound to the solar system, so in a way, that's sort of cheating.

Voyager 1 is now travelling through the cooler, denser plasma of interstellar space. While Voyager's nuclear batteries may allow it to operate until 2020, it's journey will continue onward. In 14,000 years, it will pass beyond the Oort cloud. It will make it's closest approach to one of our neighboring stars in 40,000 years. Congratulations to the Voyager team for a job well done. Thank you for your service of scientific discovery.

Friday, September 06, 2013

Mighty Big Grasshopper Jumps over Texas (and other News)

One of the more intriguing bits of news from SpaceX has been the development and testing of their Falcon 9 first stage "fly-back" technology. This is part of Spacex's overall plan to maximize the reusability of it's spacecraft and thus dramatically reduce the cost of space access. An article in Popular Mechanics gives some idea of the cost savings. Without reusable stages, Elon is expecting the Falcon 9 Heavy to deliver material to orbit for about $1000 a pound (which in and of itself is dramatically less than the $5000 to $10000 per pound that was sent up via the NASA Shuttle), but with reusable stages, he's expecting the costs could drop by as much as two orders of magnitude (but would be happy with a 50% cost reduction to start).

Their demonstrator booster/vehicle is code-named "Grasshopper". It's 10 stories tall and is an impressive sight as it maneuvers and hovers 800 feet above the Texas prairie. While some other new space companies (Armadillo Aerospace & Masten Space Systems) have developed hovering rockets, SpaceX wins the prize for frighteningly huge hovering rocket, hands down. Good luck to them. I wish SpaceX all the success in the world.

In non-related space news, Elon Musk has proposed a replacement for the California High-Speed Rail plan he calls Hyperloop. His partially evacuated tube design would shuttle capsules between Los Angeles and San Francisco at speeds up to 700+ miles per hour. Instead of high-speed trains riding on steel rails, taking up large amounts of land in the form of easements, the hyperloop runs through tubes lifted above the landscape on pylons and routed along pre-existing freeways as much as possible to take advantage of the freeways' easements. A one way hyperloop trip is planned to take about 30 minutes and could cost as little as $20, which would make taking a dinner trip to the other end of the state very practical.

I'll be quite honest: while I like it very much I'm not entirely convinced of the concept, but then again, I am nearly certain High-Speed Rail is a boondoggle (people barely ride the train as it is). Any rail or tube system has to provide significant advantages over automobile or airplane transportation, and I don't think high-speed rail can cut it (mostly because it won't be significantly cheaper than planes or cars). Hyperloop would provide those advantages, but I am somewhat concerned about (1) Safety, and (2) Scalability. If those concerns can be answered, I believe Hyperloop could be a winner.

In the decades to come, petroleum prices will force California to shift away from cars and planes to all-electric transport. I just hope we make the right decision when arriving at that all-electric transport.