Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
Compare cell phone plans using Wirefly's innovative plan comparison tool ×

Comment Re: Sixty Years Ago... (Score 1) 50

We could also use risk management metrics to make the case against spaceplanes. The shuttle had too many criticality 1 components, etc.

The Shuttle had those critical components because it was a complex vehicle with launch components on it. If you are using the risk management metrics of a side by side launch configuration with engines in it, then we are not talking about the same thing.

The CAIB report pointed out that it's risk analysis of the shuttle launch configuration produced approximately 130 impacts to the heat shield per launch. That would be eliminated in a top of stack configuration. So too would the main engines making for a less complex, less massive vehicle. A space glider.

Whether you need wings is not what I am saying, I am making the observation that none of the designs we have seen implemented produced an optimal vehicle.

Perhaps Boeing knows something we don't.

Comment Re:Sixty Years Ago... (Score 1) 50

What do you need wings for?

As I said. What my OP was suggesting was that we have not seen the most optimized design for a space plane, or more specifically, a space glider. We have never implemented a low mass glider from space.

Note: "to operate from an airport" is not an answer.

To reduce ballistic forces on re-entry, to not carry volatiles for landing, to carry more than three tons of payload back to earth, to build a simpler vehicle. Perhaps to use some of the launch energy on delivering a product produced in orbit to a specific place on earth. I don't know what possible future requirements there are. Any improvement to ablative heat shield technology, as the Dragon V2 will produce, can also be applied to a space glider.

You might be right or wrong. I'm not religiously connected to the idea of having wings in space enough to care. I accept all of the reasons you point out as pretty good reasons for not having winged space vehicles, however it still doesn't change what I saying: we have not seen the most optimized design for a space vehicle of this kind, specifically a space glider. That has nothing to do with the obsolescence of a design, idea or concept, simply a statement of fact.

My other suggestion was if there is a reason to have a space glider then the emerging market economy for space products will produce one.

Thanks for the conversation, I'll be in surgery and out of action for a while.

Comment Re:Sixty Years Ago... (Score 1) 50

It's great to see the myths of non-reusable first stage technology being dispelled.

Indeed, SpaceX has thoroughly demolished the claims of SSTO fans that reuse and low cost are somehow incompatible with staging.

We agree that this is a step forwards in getting to orbit.

We don't need wings.

They are useful though.

For what?

For operating a vehicle in atmosphere, which occurs at two critical stages of a spacecraft's mission.

Spaceplanes are dead.

Does a spaceplane have to include engines?

Take Skylon as a representative example:

No. That is specifically the design I am arguing against. Please check my post again and you will see I deliberately *exclude* the mass of the engines.

Perhaps it would make more sense if I introduced the term "Space Glider" to describe what I am talking about.

assuming it lived up to expectations, Skylon

I agree, I doubt this design would have lived up to expectations and what we have seen is failed designs for a sort of spaceplane with engines. What my OP was suggesting was that we have not seen the most optimized design for a space plane, or more specifically, a space glider.

Transportation

Domino's Will Deliver Pizza By Drone and By Robot (roboticstrends.com) 74

An anonymous Slashdot reader quotes CNN Money's report that "pizzas will soon be dropping from the heavens": Domino's demonstrated its ability to deliver food via a drone Thursday in New Zealand and plans to test actual deliveries to customers next month. "It doesn't add up to deliver a two kilogram package in a two-ton vehicle," said Scott Bush, a general manager for Domino's Pizza Enterprises, which is independent of the U.S. chain and operates in seven countries. "In Auckland, we have such massive traffic congestion it just makes sense to take to the airways."

A Domino's customer who requests a drone delivery will receive a notification when their delivery is approaching. After going outside and hitting a button on their smartphone, the drone will lower the food via a tether. Once the package is released, the drone pulls the tether back up and flies back to the Domino's store.

Robotics Trends has video from the flight, and reports that Domino's is also testing a pizza-delivering robot. Their Domino's Robotics Unit "has four wheels, is less than three feet tall, and has a heated compartment that can hold up to 10 pizzas. It can deliver pizzas within a 12.5-mile radius before needing to be recharged."

Comment Re:Sixty Years Ago... (Score 1) 50

Well, it beats making them into the world's most complicated air planes as with the space shuttle. SpaceX has proven that they can do vertical landings of the first stage intact onto both land and a seagoing barge; after a trip out of the atmosphere and to about 1/5 of orbital velocity but not into orbit.

It's great to see the myths of non-reusable first stage technology being dispelled.

That turns out to be far less expensive and complicated than a space plane. It does turn out we need a lifting body for much larger vehicles. It still doesn't have to be a plane, though.

I think you have to separate the concept from the implementation of a space plane design. SpaceX's launcher effort is less expensive and complicated than the space planes implemented so far. However both Buran and the Space Shuttle had the orbiter on the side of the stack where their heat shield was exposed to debris from the launch vehicle. So much so it was considered to be 'In-Family' because it would occur every launch to some degree.

The Space Shuttle also had all of the complexity related to the main engines which had no business being in orbit. Having the mass of those engines also complicates the infrastructure of landing. Considering also many of the political issues that interfered with the implementation of the Shuttle it wasn't the best design for a space plane.

We don't need wings.

They are useful though. The contrast is having the space plane at the top of the launcher stack, which removes the 'in-family' debris, main engine mass and, complexity issues for operating a space plane, as the X-37 demonstrates. The X-37 is covered by a shroud, however having some control surfaces at the top of a launch stack for a larger vehicle could be useful considering launchers have control surfaces near the base to balance it. A less massive orbiter means more for vehicle and payload reaching orbit and returning.

Musk has taken the pork barrelling out of launcher design and shown that it is possible to recover launcher assets. That knowledge maybe the foundation of opening up commercial space ventures paving the way for more commercial launcher platforms to become available.

The good thing about commercialization could mean someone implementing a space plane with a better design or more specific role. With those things in mind maybe we haven't seen the most optimal design for a space plane yet.

Comment Re:More political redirection (Score -1, Troll) 544

HRC and her team did everything they said they were going to do: they curated the emails, marked the ones that were personal for deletion, then used bleachbit to do the actual deletion. There is nothing new in that story.

But Trey Gowdy has demonstrated an appalling level of ignorance wrt to technology, and to the recent history of Federal level Republican politics. Oliver North, in Reagan's Iran - Contra fiasco, demonstrated full well that when it is expedient to delete something, you better damn well delete it. And not simply mark it as deleted. Gowdy is either an ignorant fool, or a disingenuous fool. But note that "fool" remains a constant with him, in this context.

To repeat: the Clinton team handled the deletions that she said she was doing in a professional manner. Gowdy just thinks that is somehow criminal that HRC is competent at handling sensitive information.

At this point I'm beginning to see a pattern shaping up where HRC is being found to be too competent at what she has been doing for fifty years, and therefore we hates her, we do, yes, we hates how this mere woman who is not a Republican is competent. Yes, we hates her.

AT&T

ISP Lobbyists Pushing Telecom Act Rewrite (dslreports.com) 76

Karl Bode, reporting for DSLReports:Telecom lobbyists are pushing hard for a rewrite of the Telecom Act, this time with a notable eye on cutting FCC funding and overall authority. AT&T donated at least $70,000 to back Republican House Speaker Paul Ryan, and clearly expects him to spearhead the rewrite and make it a priority in 2017. The push is an industry backlash to a number of consumer friendly initiatives at the FCC, including new net neutrality rules, the reclassification of ISPs under Title II, new broadband privacy rules, new cable box reform and an attempt to protect municipal broadband. AT&T's Ryan donation is the largest amount AT&T has ever donated to a single candidate, though outgoing top AT&T lobbyist Jim Cicconi has also thrown his support behind Hillary Clinton.
China

China To Crackdown On Unauthorised Radio Broadcasts (www.bgr.in) 44

An anonymous reader writes: Reportedly, in a national campaign aided by more than 30,000 airwave monitors, in over past six months, more than 500 sets of equipment for making unauthorised radio broadcasts were seized in China. The campaign, launched on February 15 by the State Council, resulted in 1,796 cases related to illegal radio stations, after 301,840 hours of monitoring from February to July, according to an online statement by the Ministry of Industry and Information Technology. The number of incidents was down by 50 per cent from April to August, the China Daily quoted the statement as saying. So-called pirate radios have appeared in most parts of China since 2015 and this "has been a channel for criminals to defraud and promote aphrodisiacs, along with counterfeit and poor-quality medicine," according to the Ministry of Public Security's Criminal Investigation Department. The operating cost of a pirate radio is low, but profit can be high. A pirate radio station that broadcasts advertisements for aphrodisiacs can pocket more than 70,000 yuan ($10,500) a month, with an overhead cost of no more than 10,000 yuan, investigators said in a post on Sina Weibo. It said most spare parts for broadcasting equipment can be bought on the internet.
Android

Opera Brings Its Free VPN Service To Android (techcrunch.com) 26

Frederic Lardinois, writing for TechCrunch: Earlier this year, Opera launched its free and unlimited VPN service for iOS; today it is bringing the same functionality to Android. Like the iOS version, the Android app is based on Opera's acquisition of SurfEasy in 2015 and allows you to surf safely when you are on a public network. While Opera's marketing mostly focuses on safety, Opera VPN also allows you to appear as if you are in the U.S., Canada, Germany, Singapore and The Netherlands, so it's also a way to route around certain geo-restrictions without having to opt for a paid service. In addition to its VPN features, the service also allows you to block ad trackers. Somewhat ironically, though, the app itself will show you some pretty unintrusive ads. "The Opera VPN app for Android sets itself apart from other VPNs by offering a completely free service; without a data limit, no log-in required, advanced Wi-Fi protection features and no need for a subscription," says Chris Houston, the president of Opera's SurfEasy VPN division, in today's announcement.

Slashdot Top Deals

Polymer physicists are into chains.

Working...