Big Data Bites Editor: Jimmy Lin, [email protected] Searching from Mars Jimmy Lin, Charles L.A. Clarke, and Gaurav Baruah • University of Waterloo ow would you search from Mars? No, somewhat familiar to a user from today. Of course, seriously. technology will have advanced dramatically, but the H The Mars to Stay concept describes a point is that we’ll likely still be searching with some- series of related proposals for establishing a perma- thing that looks like a Web search engine, engaging nent colony on Mars (see marstostay.com and www. with friends on something that looks like a social mars-one.com).1 Instead of landing astronauts there network, and purchasing items through something with the intention of bringing them home after a that looks like an e-commerce site. Just for rhetori- short visit, the plan is to send astronauts to become cal convenience, we’ll refer to brands that everyone the first Martian colonists. Such missions would be is familiar with today, so when we say “Facebook,” far less expensive, since we wouldn’t need to bring we really mean “Facebook, or whatever social net- along fuel for the return voyage (and manufactur- working service we’ll all be using in 10 years.” ing fuel on Mars is risky). Far from being a cuckoo idea, this approach to exploration has the sup- Why Search from Mars? port of many — including Elon Musk, the founder The first question is, why? More precisely, from an of SpaceX (and co-founder of PayPal and Tesla information retrieval perspective, what’s the task Motors)2 and Buzz Aldrin, the second human to set model? Mars missions, at least in the short term, foot on the moon.3 will require substantial ground support on Earth, so Scientists and engineers have worked out many our fearless Martian colonists will have access to the of the details, and the quite surprising conclusion is best minds from Earth to help with their problems. that this plan requires no new technological break- Plus, the missions will likely have been planned out throughs (that is, it’s doable with present chemical in sufficient detail that responses to most survival- rockets) and is economically feasible (to the extent critical challenges will have been already mapped that a single wealthy individual could bankroll the out. Thus, searching from Mars will likely not be a entire endeavor). Oh, and there’s no lack of volun- “Houston, we have a problem” need. teers willing to go on this one-way trip.1 We anticipate that Martian colonists will be A survey of mission plans is beyond the scope using the Web much in the same way we do today of this column, as is a discussion of numerous — reading the news, interacting with friends, watch- challenges ranging from sustaining life (air, food, ing highlights from yesterday’s game, searching for shelter, and so on) to maintaining social structures information related to a leisurely pursuit, accessing (dealing with conflict and long-term isolation) and adult entertainment, and so on. For convenience, even issues such as cost recovery (for example, we’ll call this casual Web use. One initial reaction there are proposals to turn the entire endeavor into might be: What are the colonists doing wasting a reality show). In short, there are lots of smart peo- time on Facebook? Quite the contrary, these activi- ple thinking about these issues on which we have ties are critical to the psychological and emotional no expertise. However, we do know a thing or two health of the colonists. They will continue to have about search and Big Data, and on that we will strong ties to Earth, having left behind family and most happily speculate. friends, and sustaining these connections will be How would you search from Mars? And more important to overall well-being. It seems silly and a generally, how would you use the Web from Mars? waste of resources to call up ground support to ask To make the scenario more concrete, let’s look for score updates from a football game or to obtain roughly 10 years into the future, and let’s assume a new vegetable stew recipe. Although intermedi- that “searching” and “the Web” will still feel at least ated interactions have been the norm in human 78 Published by the IEEE Computer Society 1089-7801/16/$33.00 © 2016 IEEE IEEE INTERNET COMPUTING Searching from Mars Big Data Bites space missions throughout history, it’s hard to imagine how such an approach “Big Data Bites” is a regular department in IEEE Internet Computing that aims to is sustainable for a permanent colony. deliver thought-provoking and potentially controversial ideas about all aspects of Big Indeed, we’re already moving away Data. Interested in contributing? Drop me a line! from such rigid interactions: for exam- —Jimmy Lin ple, personal Internet use is possible on the International Space Station today. Thus, we want to be able to search from Mars. the military, where the colonists are per- and we need to take into account the Another category of information manently “on-duty” and paid a salary, sun’s gravitational influence. Transit is needs will likely be scholarly search. so having disposable income is entirely accomplished by transfer orbits — inject- An important goal of Mars missions plausible. ing a vehicle into an orbit around the sun is to advance science, so our colonists that intersects the orbit of Mars at the will require access to all of the scien- The Constraints right time. This approach requires two tific literature on Earth. For example, How do we replicate on Mars the com- separate changes in velocities (delta-v’s): the colonists might want to publish plete “Web experience” on Earth? Before first, from low-Earth orbit into the trans- about breakthroughs in hydroponics, sketching out the solution, let’s first lay fer orbit, and then from the transfer orbit and thus would need the Internet in out the constraints and resources. In once we arrive at Mars. exactly the same way that an Earth- terms of the latter, the Mars colony likely There are a variety of options with bound scientist would: looking up wouldn’t be self-sufficient for a while, so different tradeoffs: the Hohmann Trans- related work, reading papers, interact- we anticipate substantial ground support fer Orbit is the most efficient in terms of ing with peers, and so on. Although it and continued investment, including fuel but is based on a particular con- might be possible to have an Earth- regular cargo supply rockets from Earth. figuration of the planets such that a side co-author handle all these inter- What about the constraints? launch window only opens up once actions, this would be awkward and Mars is sufficiently far that com- every two years.8 Bi-elliptical Trans- frustrating for the colonists, not to munication latencies are problematic. It fer Orbits take more time but require mention contrary to the workflows of takes radio signals between around 4 to less fuel.8 Conjunction class transfers modern science. For these reasons, we 24 minutes to travel to Mars, depend- are our best bet, with current or near- want to be able to search from Mars. ing on the relative positions of the future rocket technology: they’ll get us Our goal is to make searching from planetary bodies, so we need to cope to Mars in between 120 to 270 days,9 Mars and Web use in general as close with a roundtrip latency of between 8 which is in line with the historical aver- to the experience from Earth as pos- and 48 minutes.6 That means a Skype age: missions have taken between 150 sible. This contrasts with alternative call between Earth and Mars is out of to 300 days to reach Mars over the last approaches built on the idea of “slow the question, and we’re not likely to half century.10 As an aside, if we can search”4 and asynchronous search mod- figure out faster-than-light communi- overcome the political objections of els.5 It will be a while before we have cation anytime soon (perhaps ever). using nuclear rockets (for example, as Amazon Prime on Mars, but it’s perhaps There exist technologies built around outlined in the Orion project), it might reasonable to expect that a colonist laser-based communication where it’s be possible to cut the travel time to could purchase (small) personal items possible to achieve good bandwidth around two months.11 from Amazon and have it delivered on between Earth and Mars. The Lunar Finally, it’s also worth mentioning the next supply rocket (estimated deliv- Laser Communications Demonstration the concept of a Mars cycler, which is ery time: eight months). Furthermore, achieved a 622-Mbps downlink and a a vehicle in a special orbit around the the colonists will want to buy presents 20-Mbps uplink between the Earth and sun that encounters Earth and Mars for friends and family. Although the lat- the Moon,7 so something like this to on a regular basis.12 Instead of inser- est holographic display might be too Mars is technologically feasible. If we tion into Martian orbit, a cycler keeps large for shipping to Mars, it still makes need more bandwidth, we simply build flying in an endless loop (around the a great Father’s Day gift. Such transac- more satellites, and thus it’s reasonable sun) — payloads “hitch” a ride on the tions, as well as purchasing the latest to count on substantial (but not infinite) cycler and then “get off” at the right Kindle release or the digital plans for the bandwidth between Earth and Mars.