SpaceX vs Nasa to the moon

A recent article on the website 'the conversation' compares and contrasts two rockets being developed for space travel: SpaceX vs Nasa: who will get us to the Moon first? Here's how their latest rockets compare, by Gareth Dorrian (Post Doctoral Research Fellow in Space Science, University of Birmingham) and Ian Whittaker (Senior Lecturer in Physics, Nottingham Trent University). Accompanying image is from the article.

Link to article: https://theconversation.com/spacex-vs-nasa-who-will-get-us-to-the-moon-first-heres-how-their-latest-rockets-compare-154199

The first part of the article gives background information about rockets, and then describes first the SpaceX Starship and then Nasa's Space Launch System (SLS). From this information, students could look into the relative advantages and disadvantages further. For example, SpaceX's launch vehicle burns a combination of liquid methane and liquid oxygen, while NASA's SLS core stage contains liquid hydrogen and liquid oxyen.

"The [SpaceX launch vehicle's] rocket will provide 15 million pounds of thrust at launch" vs. Nasa: "The core stage of the rocket is augmented by two solid rocket boosters, attached to its sides, providing a total combined thrust of 8.2 million pounds at launch."

The final paragraph sums up the pros and cons of each:

"Ultimately it is a competition between an agency that has had years of testing and experience but is limited by a fluctuating taxpayer budget and administration policy changes, and a company relatively new to the game but which has already launched 109 Falcon 9 rockets with a 98% success rate and has a dedicated long-term cash flow."

Students could first compare their first impressions of the two approaches, and then gather information to support one or the other. In a classroom setting, a debate could be organized (SpaceX or Nasa?). In a distance-learning situation, students could submit their "argument" supporting the one they think will be the 'winner' and why. Fellow students with an opposing view could choose one to read and comment on.

Throughout the semester, students can follow updates about the two rockets since both SpaceX and Nasa are often in the news and on many scientific/technical websites. Areas to focus on are not only each rocket's advantages and disadvantages, but also the differences in innovation development between a private firm and a government agency.

The article has relevant examples of language used to compare and contrast. For example:

• but X is also
• both X and Y are developing
• which is approximately twice as much as
• X and Y are both
• their main difference from X is that
• about 5% more than
• which is smaller and lighter than
• a task that current Xs are currently not capable of performing
• so there is a higher cost with X, both in materials and environmentally
• which is potentially more than
• whereas

There are also examples of the tenses that my students find most difficult to use.

Examples of the present perfect tense (which has no reference to a point of time in the past):

• No-one has visited the Moon since 1972.
• Nasa has selected the private company SpaceX to be part of its commercial spaceflight operations
• Musk has also stated that a crewed Martian mission could take place as early as 2024
• Ultimately it is a competition between an agency that has had years of testing and experience
• a company relatively new to the game but which has already launched 109 Falcon 9 rockets

Contrasted with simple past tense, with related past time reference underlined:

• A recent test flight of the Starship prototype, the SN8, successfully demonstrated ... Unfortunately there was a malfunction in one of the Raptor engines and the SN8 crashed on landing.
• three of which were used on the previous Space Shuttle
• a test fire of the SLS core stage was stopped a minute into the eight-minute test

There are many examples of the use of the simple present tense to indicate "something that is true in the present; that happens regularly in the present; that is always true" (according to the British Council website https://learnenglish.britishcouncil.org/english-grammar-reference/present-simple) -- Rockets go through multiple stages to get into orbit; the rocket becomes lighter; the Starship flips into a vertical position and uses its on-board Raptor engines; etc.

But my students find it more difficult to decide when to use the present progressive tense. So the examples from the article are very useful as illustrations of something happening currently:

• the firm is also pursuing its own space exploration agenda
• both Nasa and SpaceX are developing new heavy lift rockets
• The spacecraft is maturing rapidly
• a task that current Nasa rockets are currently not capable of performing
• "I don't think we're looking at a significant design change."
• they are running #dearMoon - a project involving lunar space tourism

Finally, since the article includes information about planned future developments, there is the use of the future tense with "will": SpaceX's launch system will be comprised of two stages; the rocket will provide; it will have sufficient thrust; this will lift the spacecraft; etc. But the future is also referred to with the simple present tense and with phrases useful for students to learn:

• The upper stage is intended to lift the attached payload
• The core stage and booster rockets are unlikely to be reusable
• It is designed to evolve to larger stages
• which is potentially more than Starship
• Artemis 2 is planned as the first crewed mission
• and is expected to launch in August 2023
• a crewed Martian mission could take place as early as 2024

The article ends with the sentence: "Whoever reaches the Moon first will inaugurate a new era of exploration of a world which still has much scientific value." This alone could provide much discussion or response: Who is likely to "reach the Moon first"; what the impact could be of "who" the first would be; what a "new era" would look like; what aspects of "exploration" would be the most useful or least harmful; and what examples of "scientific value" would be generated.

Bonus: The article's website has a 2:21-minute film clip of the Starship SN8 High-altitude flight re-cap. There is no narration except for the voice counting liftoff, but the stages are labeled on the screen. There is also a labeled diagram of the stages of Nasa's SLS as well as the illustration comparing rockets that I have used for this post.